#213: fix ZDOTDIR credential scrub gate + directory under memberHerdrSocket

The memberCredentials.policy: allow-list ZDOTDIR scrub decided zsh-vs-not
using fleetd's own process $SHELL and wrote the generated scrub dir into
fleetd's own java.io.tmpdir. Under memberHerdrSocket: (member panes run as
a different OS user than fleetd's own process) this silently protects
nothing: the wrong shell decides the gate, and the directory can be
unreachable to the member.

- New FleetConfig.memberLoginShell: the member OS user's login shell,
  only ever read when memberHerdrSocket: is configured; fleetd's own
  $SHELL keeps deciding everything when memberHerdrSocket: is absent
  (byte-identical to before).
- HerdrPeerLauncher.applyEnvironmentAllowListPolicy: memberHerdrSocket +
  memberLoginShell not configured/non-zsh falls back to the CB-596
  sentinel overlay (warn loudly, never refuse to spawn). memberHerdrSocket
  + zsh memberLoginShell generates the ZDOTDIR under the configured
  worktreeRoot instead of java.io.tmpdir, shared with the existing
  worktreeGroup (reused, not a new key).
- EnvAllowListScrub: new generate(parentDir, allowedNames, group) overload
  shares the generated directory via pure-Java POSIX group ownership
  (rwxr-x--- dir, rw-r----- files) — no external process spawn.
- fleetd.example.yaml documents memberLoginShell: and worktreeGroup:'s
  reuse for the scrub directory (the live fleetd.yaml is gitignored).

4 new tests in HerdrPeerLauncherAllowListWiringTest cover the acceptance
criteria; 3 of the 4 were watched failing against the pre-fix code.

fleetd/fleetd.example.yaml

@@ -117,6 +117,15 @@ herdrSocket: ~/.config/herdr/herdr.sock
 # Optional socket for member panes. Omit this to use herdrSocket for both leads and members.
 # memberHerdrSocket: /Users/member/.config/herdr/herdr.sock
 
+# fleetd #213: the login shell the member OS user (memberHerdrSocket above) actually runs. ONLY
+# read when memberHerdrSocket is set — fleetd's own $SHELL says nothing about a pane running
+# under a different OS user, and there is no channel to ask herdr for that user's shell, so this
+# must be told rather than guessed. Absent, blank, or anything not ending in "zsh" is treated the
+# same as "not zsh": the memberCredentials.policy: allow-list ZDOTDIR scrub (see worktreeGroup
+# below) is skipped in favour of the weaker CB-596 sentinel overlay — a degraded control, never a
+# refusal to spawn. When memberHerdrSocket is absent this key is never consulted at all.
+# memberLoginShell: /bin/zsh
+
 # How member sessions are spawned. Define one or more named profiles (backends) under
 # `profiles`; each key is the profile name (also the ccs profile). A profile says only WHICH
 # BACKEND — model, CLI adapter, credentials, cost. It says nothing about what a member spawned on
@@ -643,6 +652,13 @@ guard:
 # CAUTION: this isolates credentials, not the repository — a member in the group can still
 # write the operator's git objects and refs in the shared repo. The operator running fleetd
 # must already be a member of the named group, or every provisioning spawn fails loudly.
+#
+# fleetd #213: this is also the ONE group the memberCredentials.policy: allow-list ZDOTDIR scrub
+# reuses when memberHerdrSocket is set — deliberately not a second config key. Under
+# memberHerdrSocket, the scrub directory is generated under worktreeRoot (never java.io.tmpdir,
+# which the member OS user cannot reach) and shared read-only with this group. If worktreeGroup
+# is unset while memberHerdrSocket is set, the scrub cannot be guaranteed reachable by the member,
+# so fleetd falls back to the weaker CB-596 sentinel overlay instead (a WARN names the gap).
 # worktreeGroup: fleet-workers
 
 # Session lifecycle limits (CB-303). All knobs are opt-in; omit or set to null to keep

fleetd/src/main/java/dev/ltms/fleet/config/FleetConfig.java

@@ -84,6 +84,18 @@ import java.util.Set;
  *                      <strong>This isolates credentials, not the repository</strong>: a member in
  *                      the group can still write the operator's git objects and refs in the shared
  *                      repo. See {@link dev.ltms.fleet.session.Worktrees#shareWithGroup}.
+ * @param memberLoginShell fleetd #213: the login shell the member's OS user actually runs, ONLY
+ *                      meaningful (and only ever read) when {@code memberHerdrSocket} is
+ *                      configured — that mode spawns member panes under a different OS user than
+ *                      fleetd's own process, so fleetd's own {@code $SHELL} says nothing about what
+ *                      that pane runs. There is no channel to ask herdr for another user's shell, so
+ *                      this must be told, never guessed. {@code null}/blank (or a value not ending
+ *                      in {@code zsh}) is treated the same as "not zsh": the {@code
+ *                      memberCredentials.policy: allow-list} ZDOTDIR scrub is skipped in favour of
+ *                      the CB-596 sentinel overlay — a degraded control, never a refusal to spawn.
+ *                      When {@code memberHerdrSocket} is NOT configured this field is never
+ *                      consulted at all; fleetd keeps reading its own {@code $SHELL}, exactly as
+ *                      before this field existed.
  */
 @JsonIgnoreProperties(ignoreUnknown = true)
 public record FleetConfig(
@@ -107,7 +119,20 @@ public record FleetConfig(
         Integer quarantineCooldownSeconds,
         MemberCredentials memberCredentials,
         Coordinator coordinator,
-        String worktreeGroup) {
+        String worktreeGroup,
+        String memberLoginShell) {
+
+    /** Back-compat form before the {@code memberLoginShell} key was added. */
+    public FleetConfig(Bind bind, String herdrSocket, String memberHerdrSocket, Map<String, Profile> profiles,
+                         Guard guard, String worktreeRoot, Lifecycle lifecycle, Integer spawnReadyTimeoutMs,
+                         Integer spawnReadyPollMs, Broker broker, Primary primary, Fleet fleet,
+                         LeadHeartbeat leadHeartbeat, Health health, String placement, Auth auth,
+                         ConfigReload configReload, Integer quarantineCooldownSeconds,
+                         MemberCredentials memberCredentials, Coordinator coordinator, String worktreeGroup) {
+        this(bind, herdrSocket, memberHerdrSocket, profiles, guard, worktreeRoot, lifecycle, spawnReadyTimeoutMs,
+                spawnReadyPollMs, broker, primary, fleet, leadHeartbeat, health, placement, auth,
+                configReload, quarantineCooldownSeconds, memberCredentials, coordinator, worktreeGroup, null);
+    }
 
     /** Back-compat form before the {@code worktreeGroup} key was added. */
     public FleetConfig(Bind bind, String herdrSocket, String memberHerdrSocket, Map<String, Profile> profiles,
@@ -118,7 +143,7 @@ public record FleetConfig(
                          MemberCredentials memberCredentials, Coordinator coordinator) {
         this(bind, herdrSocket, memberHerdrSocket, profiles, guard, worktreeRoot, lifecycle, spawnReadyTimeoutMs,
                 spawnReadyPollMs, broker, primary, fleet, leadHeartbeat, health, placement, auth,
-                configReload, quarantineCooldownSeconds, memberCredentials, coordinator, null);
+                configReload, quarantineCooldownSeconds, memberCredentials, coordinator, null, null);
     }
 
     /** Back-compat form before the {@code coordinator:} block was added. */
@@ -1346,7 +1371,7 @@ public record FleetConfig(
             "bind", "herdrSocket", "memberHerdrSocket", "profiles", "guard", "worktreeRoot",
             "lifecycle", "spawnReadyTimeoutMs", "spawnReadyPollMs", "broker", "primary", "fleet",
             "leadHeartbeat", "health", "placement", "auth", "configReload", "quarantineCooldownSeconds",
-            "memberCredentials", "coordinator", "worktreeGroup");
+            "memberCredentials", "coordinator", "worktreeGroup", "memberLoginShell");
 
     /** Load and validate config from {@code path}. */
     public static FleetConfig load(Path path) {
@@ -1966,9 +1991,12 @@ public record FleetConfig(
         // and this ticket's Coordinator is config-only anyway (nothing yet reads it at startup).
         // worktreeGroup is left as-is (fleetd #185 stage 3): null/blank is "off", and there is no
         // sane non-null default — an OS group name is operator-specific.
+        // memberLoginShell is left as-is (fleetd #213), like worktreeGroup: null/blank is "not
+        // configured", and there is no sane non-null default — a member's login shell is
+        // operator-specific and only meaningful when memberHerdrSocket is also set.
         return new FleetConfig(b, herdrSocket, memberHerdrSocket, profiles, g, worktreeRoot, l, timeout, pollMs,
                 broker, primary, f, leadHeartbeat, health, placementOrDefault, a, configReload,
-                quarantineCooldown, mc, coordinator, worktreeGroup);
+                quarantineCooldown, mc, coordinator, worktreeGroup, memberLoginShell);
     }
 
     /**

fleetd/src/main/java/dev/ltms/fleet/member/EnvAllowListScrub.java

@@ -7,6 +7,9 @@ import java.io.IOException;
 import java.io.UncheckedIOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.attribute.GroupPrincipal;
+import java.nio.file.attribute.PosixFileAttributeView;
+import java.nio.file.attribute.PosixFilePermissions;
 import java.time.Duration;
 import java.time.Instant;
 import java.util.ArrayList;
@@ -116,6 +119,70 @@ public final class EnvAllowListScrub {
         }
     }
 
+    /**
+     * fleetd #213: as {@link #generate(Path, Set)}, plus share the generated directory with
+     * {@code group} — the member OS user's group (the operator's existing {@code worktreeGroup:}
+     * name, reused rather than inventing a second one) — so a member running under a different OS
+     * user than fleetd's own process can still read what it needs from a directory placed outside
+     * {@code java.io.tmpdir}. {@code group} null/blank ⇒ identical to {@link #generate(Path, Set)};
+     * this is the single-daemon (no {@code memberHerdrSocket}) shape, where the pane is fleetd's own
+     * uid and no group sharing is needed.
+     *
+     * @throws UncheckedIOException also when {@code group} does not resolve on this host, or a
+     *                              group-ownership/permission call is refused — the same "fail
+     *                              loudly rather than start unprotected" contract as above: a scrub
+     *                              the configured member user cannot even read is not a working
+     *                              control.
+     */
+    public static Path generate(Path parentDir, Set<String> allowedNames, String group) {
+        Path dir = generate(parentDir, allowedNames);
+        if (group != null && !group.isBlank()) {
+            shareWithGroup(dir, group);
+        }
+        return dir;
+    }
+
+    /**
+     * chgrp/chmod-equivalent over the freshly generated directory and the startup files already
+     * written into it: owner keeps full access, {@code group} gets traverse+read on the directory
+     * ({@code rwxr-x---}, so a login shell under that group can find and source the files) and
+     * read-only on each file ({@code rw-r-----}) — deliberately no group WRITE anywhere, since a
+     * member never needs to add or change fleetd's own generated scrub. (The scrub script's own
+     * report write inside the pane consequently fails closed rather than open — see {@code
+     * scrub.zsh}'s trailing {@code 2>/dev/null} — which {@link
+     * dev.ltms.fleet.member.HerdrPeerLauncher#releaseZdotdir} already treats as "cannot be
+     * confirmed to have run" rather than success.)
+     */
+    private static void shareWithGroup(Path dir, String group) {
+        try {
+            GroupPrincipal principal = dir.getFileSystem().getUserPrincipalLookupService()
+                    .lookupPrincipalByGroupName(group);
+            setGroupAndPermissions(dir, principal, "rwxr-x---");
+            try (Stream<Path> entries = Files.list(dir)) {
+                for (Path file : entries.toList()) {
+                    setGroupAndPermissions(file, principal, "rw-r-----");
+                }
+            }
+        } catch (IOException e) {
+            throw new UncheckedIOException("cannot share generated ZDOTDIR " + dir + " with group '"
+                    + group + "' — the group must exist, and the fleetd operator ("
+                    + System.getProperty("user.name") + ") must be a member of it", e);
+        } catch (UnsupportedOperationException e) {
+            throw new UncheckedIOException("cannot share generated ZDOTDIR " + dir + " with group '"
+                    + group + "' — this filesystem does not support POSIX group ownership",
+                    new IOException(e));
+        }
+    }
+
+    private static void setGroupAndPermissions(Path path, GroupPrincipal group, String perms) throws IOException {
+        PosixFileAttributeView view = Files.getFileAttributeView(path, PosixFileAttributeView.class);
+        if (view == null) {
+            throw new IOException("POSIX file attributes are not supported for " + path);
+        }
+        view.setGroup(group);
+        Files.setPosixFilePermissions(path, PosixFilePermissions.fromString(perms));
+    }
+
     /** One operator-sourcing startup file: source the {@code $HOME} counterpart, change nothing else. */
     private static String homeSourcingFile(String name) {
         return """

fleetd/src/main/java/dev/ltms/fleet/member/HerdrPeerLauncher.java

@@ -112,6 +112,12 @@ public abstract class HerdrPeerLauncher implements PeerLauncher {
      * daemon's own process is started the same way (a login shell sourcing the same secret store —
      * see CB-592's investigation of {@code secrets.sh}), so on a single-host deployment its env
      * mirrors what the pane's login shell is about to export.
+     *
+     * <p>fleetd #185 stage 2: that mirroring assumption holds only while the member pane runs under
+     * the SAME OS user as the daemon. When {@code memberHerdrSocket:} is configured, member panes
+     * run on a second herdr owned by a different user — different {@code $HOME}, different {@code
+     * secrets.sh}, different environment entirely — so this field's data no longer describes what a
+     * member pane inherits. See {@link #logCredentialGap} for how that mode is handled.
      */
     private final Supplier<Set<String>> hostEnvNames;
 
@@ -1071,6 +1077,29 @@ public abstract class HerdrPeerLauncher implements PeerLauncher {
      * name. It stays a one-off decision because it is a live handle to the operator's ssh-agent, not
      * a value — a member holding it can sign with every key the agent holds, so letting it ride in
      * on the generic {@code allow:} list would hand that out for an unrelated reason.
+     *
+     * <p>fleetd #213: which shell decides the zsh gate, and where the generated directory lives,
+     * both depend on whether {@code memberHerdrSocket:} is configured — see {@link
+     * #memberHerdrSocketConfigured()}'s javadoc for why fleetd's own {@code $SHELL} and {@code
+     * java.io.tmpdir} describe the wrong process once member panes run under a different OS user.
+     * <ul>
+     *   <li>{@code memberHerdrSocket} ABSENT (today's only mode): byte-identical to before this
+     *       fix — fleetd's own {@code $SHELL} decides zsh, and the directory is generated under
+     *       {@code java.io.tmpdir}.</li>
+     *   <li>{@code memberHerdrSocket} PRESENT: the configured {@code memberLoginShell:} decides
+     *       zsh instead — fleetd's own {@code $SHELL} is never consulted, since it names a
+     *       different user's shell, not the member's. Absent/non-zsh falls back exactly like the
+     *       non-zsh case below. When it IS zsh, the directory still cannot go under {@code
+     *       java.io.tmpdir} (mode 0700, unreadable by another uid — the exact gap fleetd #213
+     *       exists to close), so it is generated under {@code worktreeRoot} instead and shared
+     *       read-only with {@code worktreeGroup} — the same group {@link
+     *       dev.ltms.fleet.session.Worktrees#shareWithGroup} already uses, reused rather than
+     *       inventing a second group key. Either one missing means the scrub cannot be guaranteed
+     *       reachable by the member, which is the same "cannot guarantee the scrub runs" case as a
+     *       non-zsh shell, so it gets the identical fallback.</li>
+     * </ul>
+     * In every branch: never refuse to spawn. A degraded credential control must not become an
+     * outage for an opt-in feature.
      */
     private Path applyEnvironmentAllowListPolicy(FleetConfig.Profile cfg, Launch launch) {
         FleetConfig.MemberCredentials creds = memberCredentials == null ? null : memberCredentials.get();
@@ -1078,8 +1107,14 @@ public abstract class HerdrPeerLauncher implements PeerLauncher {
             return null;
         }
         Set<String> allowed = derivedAllowedNames(creds, launch);
-        String loginShell = resolveEnv("SHELL");
-        boolean zsh = loginShell != null && (loginShell.endsWith("/zsh") || loginShell.equals("zsh"));
+        boolean memberHerdrSocket = memberHerdrSocketConfigured();
+        // fleetd #213 defect 1: under memberHerdrSocket the member pane runs as a DIFFERENT OS
+        // user, so fleetd's own $SHELL says nothing about what that pane runs — resolveEnv("SHELL")
+        // must not even be called on this path, only the explicit memberLoginShell: config can
+        // answer it. With memberHerdrSocket absent, nothing here changes: fleetd's own $SHELL is
+        // still the input, exactly as before this fix.
+        String loginShell = memberHerdrSocket ? configuredMemberLoginShell() : resolveEnv("SHELL");
+        boolean zsh = isZshShell(loginShell);
         if (!zsh) {
             // A non-zsh login shell ignores ZDOTDIR entirely: NO scrub would run, so pretending
             // otherwise would be worse than saying so. Warn loudly and fall back to the CB-596
@@ -1093,13 +1128,35 @@ public abstract class HerdrPeerLauncher implements PeerLauncher {
             logCredentialGap(creds, null);
             return null;
         }
+        Path parentDir;
+        String group = null;
+        if (memberHerdrSocket) {
+            // fleetd #213 defect 2: java.io.tmpdir is fleetd's own per-user temp dir (mode 0700 on
+            // macOS) — a member running as a different uid cannot even traverse it, let alone read
+            // the generated files. worktreeRoot is the only configured location a different-uid
+            // member can be given access to, and only WITH worktreeGroup to grant that access —
+            // absent either, the scrub cannot be guaranteed reachable, so this falls back exactly
+            // like the non-zsh case above rather than generating a directory nothing can read.
+            parentDir = memberScrubParentDir();
+            group = memberGroup();
+            if (parentDir == null || group == null) {
+                warnCannotShareScrubDirectory();
+                overlayBlockedCredentials(launch.env(), creds);
+                logCredentialGap(creds, null);
+                return null;
+            }
+        } else {
+            parentDir = Path.of(System.getProperty("java.io.tmpdir"));
+        }
         // Only reached when the scrub is actually about to run — the count below describes that
         // scrub, so it must not be logged before this gate (see the non-zsh branch above). Same
         // reasoning gates logCredentialGap's wording: passing the derived `allowed` set (non-null)
         // here, and ONLY here, is what tells it the scrub will really blank an unkept name — #192.
         logAllowListCoverage(allowed);
         logCredentialGap(creds, allowed);
-        Path dir = EnvAllowListScrub.generate(Path.of(System.getProperty("java.io.tmpdir")), allowed);
+        Path dir = memberHerdrSocket
+                ? EnvAllowListScrub.generate(parentDir, allowed, group)
+                : EnvAllowListScrub.generate(parentDir, allowed);
         launch.env().put("ZDOTDIR", dir.toAbsolutePath().toString());
         log.info("memberCredentials policy=allow-list: profile={} generated ZDOTDIR {} — derived "
                         + "allow-list holds {} name(s); the pane reports allowed N of M at release",
@@ -1107,6 +1164,55 @@ public abstract class HerdrPeerLauncher implements PeerLauncher {
         return dir;
     }
 
+    /** True when {@code shell} is a zsh login shell path or bare name — the ZDOTDIR gate. */
+    private static boolean isZshShell(String shell) {
+        return shell != null && (shell.endsWith("/zsh") || shell.equals("zsh"));
+    }
+
+    /**
+     * fleetd #213: the configured {@code memberLoginShell:}, or {@code null} when unconfigured.
+     * Called ONLY from the {@code memberHerdrSocket}-configured branch of {@link
+     * #applyEnvironmentAllowListPolicy} — fleetd's own {@code $SHELL} is never read on that path.
+     * {@link #config} being {@code null} (an older test call site, or a launcher that never
+     * threaded the full config through) is treated the same as "not configured".
+     */
+    private String configuredMemberLoginShell() {
+        FleetConfig cfg = config == null ? null : config.get();
+        return cfg == null ? null : cfg.memberLoginShell();
+    }
+
+    /**
+     * fleetd #213: {@code worktreeRoot}, as the ZDOTDIR scrub's parent directory under {@code
+     * memberHerdrSocket}, or {@code null} when unconfigured — the same "cannot guarantee the scrub
+     * runs" gap as {@link #memberGroup()} being unset (see {@link
+     * #applyEnvironmentAllowListPolicy}). Deliberately no sibling-of-repo-root default here, unlike
+     * {@code GitWorktrees}' own {@code worktreeRoot} resolution: that default is a convenience for
+     * provisioning a worktree that will exist regardless, whereas an unconfigured value here means
+     * fleetd has no operator-endorsed location to put a credential-bearing directory a different OS
+     * user must reach, so falling back to the overlay is the honest answer, not a guess.
+     */
+    private Path memberScrubParentDir() {
+        FleetConfig cfg = config == null ? null : config.get();
+        if (cfg == null || cfg.worktreeRoot() == null || cfg.worktreeRoot().isBlank()) {
+            return null;
+        }
+        return Path.of(cfg.worktreeRoot());
+    }
+
+    /**
+     * fleetd #213: the configured {@code worktreeGroup:}, or {@code null} when unset/blank. Reuses
+     * the group {@link dev.ltms.fleet.session.Worktrees#shareWithGroup} already establishes for
+     * provisioned worktrees, rather than a second group key — see {@link
+     * #applyEnvironmentAllowListPolicy}.
+     */
+    private String memberGroup() {
+        FleetConfig cfg = config == null ? null : config.get();
+        if (cfg == null || cfg.worktreeGroup() == null || cfg.worktreeGroup().isBlank()) {
+            return null;
+        }
+        return cfg.worktreeGroup();
+    }
+
     /**
      * The full kept-name set for this spawn: the profile-derived names, unioned with {@code
      * memberCredentials.allow:} (CB-633 follow-up — previously ignored by this whole policy), the
@@ -1164,6 +1270,30 @@ public abstract class HerdrPeerLauncher implements PeerLauncher {
         }
     }
 
+    /** Guards {@link #warnCannotShareScrubDirectory} to one WARN per launcher instance. */
+    private final AtomicBoolean cannotShareScrubDirWarned = new AtomicBoolean();
+
+    /**
+     * fleetd #213: {@code memberHerdrSocket} is configured and the member login shell IS zsh, but
+     * {@code worktreeRoot} and/or {@code worktreeGroup} is missing, so the generated ZDOTDIR cannot
+     * be placed anywhere the member's OS user can reach — {@code java.io.tmpdir} is fleetd's own
+     * 0700 temp dir, unreadable by another uid, which is the exact gap this ticket exists to close.
+     * Say so once per launcher instance, instead of either generating a directory nothing can read
+     * (protection theatre) or refusing to spawn (turning a degraded credential control into an
+     * outage for an opt-in feature).
+     */
+    private void warnCannotShareScrubDirectory() {
+        if (cannotShareScrubDirWarned.compareAndSet(false, true)) {
+            log.warn("memberCredentials policy=allow-list: memberHerdrSocket is configured and the "
+                    + "member login shell is zsh, but worktreeRoot and/or worktreeGroup is not "
+                    + "configured — the generated ZDOTDIR cannot be placed where the member's OS "
+                    + "user can read it (java.io.tmpdir is fleetd's own, unreadable by another uid), "
+                    + "so the scrub cannot be guaranteed to run. Falling back to the CB-596 sentinel "
+                    + "overlay. Configure both worktreeRoot and worktreeGroup to enable the "
+                    + "allow-list scrub under memberHerdrSocket.");
+        }
+    }
+
     /**
      * CB-633 teardown half: read the pane's scrub report (the denominator report the generated
      * scrub wrote) and delete the directory. Called from {@link #stop}, which is the one funnel
@@ -1230,6 +1360,67 @@ public abstract class HerdrPeerLauncher implements PeerLauncher {
      */
     private final AtomicBoolean allowListGapLogged = new AtomicBoolean();
 
+    /**
+     * fleetd #185 stage 2: guards {@link #warnUnknownMemberEnvironment} to one WARN per launcher
+     * instance, not one per spawn — the same one-per-instance shape as {@link #unprotectedGapLogged}
+     * and {@link #allowListGapLogged}, kept as its own flag for the same reason those two are split:
+     * this mode is orthogonal to which of the other two branches would otherwise have fired.
+     */
+    private final AtomicBoolean unknownMemberEnvironmentWarned = new AtomicBoolean();
+
+    /**
+     * fleetd #185 stage 2: whether {@code memberHerdrSocket:} is configured, i.e. member panes run
+     * on a second herdr owned by a different OS user than the daemon's own process. Re-read from the
+     * live config on every call (same hot-reload shape as {@link #memberCredentials}), never cached,
+     * so a config reload takes effect on the next spawn without a restart.
+     *
+     * <p>{@link #config} is {@code null} on any call site that never threaded the full config
+     * through (every production {@code HerdrPeerLauncher} does; a handful of older tests do not) —
+     * treated the same as "not configured", which is the correct, permissive default: it is exactly
+     * today's single-daemon behaviour.
+     */
+    private boolean memberHerdrSocketConfigured() {
+        if (config == null) {
+            return false;
+        }
+        FleetConfig cfg = config.get();
+        return cfg != null && cfg.memberHerdrSocket() != null && !cfg.memberHerdrSocket().isBlank();
+    }
+
+    /**
+     * fleetd #185 stage 2: the single replacement WARN for {@link #logCredentialGap}'s usual
+     * conclusions when {@code memberHerdrSocket:} is configured. {@link #hostEnvNames} (and
+     * everything derived from it — {@code known}/{@code allow} coverage, the allow-list scrub's
+     * derived set) describes the DAEMON's own environment; under this config key member panes run as
+     * a different OS user with a different environment entirely, so neither "every member pane
+     * inherits them UNBLOCKED" nor "the scrub blanks them" is evidence-backed here — both would be
+     * reporting on the wrong process. Logged once, names the config key, and states the honest
+     * conclusion: the gap for member panes is UNKNOWN, not clean, so {@code memberCredentials} cannot
+     * be verified from this daemon. The one count it does report is scoped explicitly to fleetd's own
+     * environment, never presented as if it said anything about the member's — see {@link
+     * #logCredentialGap}'s javadoc for why this branch exists.
+     */
+    private void warnUnknownMemberEnvironment(FleetConfig.MemberCredentials creds) {
+        if (!unknownMemberEnvironmentWarned.compareAndSet(false, true)) {
+            return;
+        }
+        Set<String> covered = new HashSet<>(creds.known());
+        covered.addAll(creds.allow());
+        Set<String> hostNames = hostEnvNames.get();
+        long gapInFleetdsOwnEnv = hostNames.stream()
+                .filter(name -> CREDENTIAL_SHAPED_NAME.matcher(name).matches())
+                .filter(name -> !covered.contains(name))
+                .count();
+        log.warn("memberCredentials gap: memberHerdrSocket is configured, so member panes run under "
+                        + "a different OS user than fleetd's own process, with a different environment "
+                        + "entirely — fleetd has no channel to read that user's environment. {} of the "
+                        + "{} names in fleetd's OWN environment are credential-shaped and not on "
+                        + "known:/allow:, but that count describes fleetd's process, not the member "
+                        + "herdr's. The credential gap for member panes is UNKNOWN, not clean, and "
+                        + "memberCredentials cannot be verified from here.",
+                gapInFleetdsOwnEnv, hostNames.size());
+    }
+
     /**
      * CB-596 criterion 4: a credential-shaped host env var name on neither {@code known} nor
      * {@code allow} is not silently allowed — it is reported. {@link #hostEnvNames} enumerates the
@@ -1258,8 +1449,22 @@ public abstract class HerdrPeerLauncher implements PeerLauncher {
      * (same severity, and same guard, as the deny-by-default case — a name genuinely reaching a
      * member unprotected is equally serious whichever path put it there), and the names it says are
      * blanked keep the INFO.
+     *
+     * <p>fleetd #185 stage 2: everything above assumes the member pane runs under the same OS user
+     * as the daemon, so {@link #hostEnvNames} mirrors what the pane inherits — see that field's
+     * javadoc. When {@code memberHerdrSocket:} is configured that assumption is false: the member
+     * pane runs on a second herdr owned by a <em>different</em> user, and neither conclusion below
+     * ("inherits them UNBLOCKED" / "the scrub blanks them") is backed by evidence about that user's
+     * environment. So this method checks that first and, when configured, reports the honest
+     * "unknown, not clean" conclusion instead — see {@link #warnUnknownMemberEnvironment}. When
+     * {@code memberHerdrSocket:} is absent (the default, and the only mode this host runs) this
+     * branch is never taken and every line below is unchanged.
      */
     private void logCredentialGap(FleetConfig.MemberCredentials creds, Set<String> effectiveAllowed) {
+        if (memberHerdrSocketConfigured()) {
+            warnUnknownMemberEnvironment(creds);
+            return;
+        }
         Set<String> covered = new HashSet<>(creds.known());
         covered.addAll(creds.allow());
         List<String> gap = hostEnvNames.get().stream()

fleetd/src/main/java/dev/ltms/fleet/msg/MessageService.java

@@ -9,6 +9,7 @@ import dev.ltms.fleet.metrics.Metrics;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.UUID;
 import java.util.concurrent.CompletableFuture;
@@ -167,6 +168,12 @@ public final class MessageService {
     private static final class Task {
         private final String ticket;
         private final String target;
+        /**
+         * When this task was created (#137 fix): the tiebreaker for which of several open tasks on
+         * one target gets a recovered reply in {@link #abandon} — the oldest, since it is the one
+         * that has been waiting longest.
+         */
+        private final long createdNanos;
         private final CompletableFuture<Reply> future = new CompletableFuture<>();
         /**
          * When {@link #future} resolved, or {@code null} while it is still pending — the clock
@@ -184,6 +191,7 @@ public final class MessageService {
         private Task(String ticket, String target, LongSupplier nowNanos) {
             this.ticket = ticket;
             this.target = target;
+            this.createdNanos = nowNanos.getAsLong();
             future.whenComplete((reply, ex) -> completedNanos = nowNanos.getAsLong());
         }
     }
@@ -375,6 +383,19 @@ public final class MessageService {
      * {@link Rendezvous#resolveQuestion} must keep today's {@code NO_WAITER} behaviour — questions
      * are interactive and must never be queued.
      *
+     * <p><strong>Ambiguous match also falls to the inbox.</strong> {@link #askAnsweredAsyncTasks}
+     * cannot actually return more than one entry today (see its own javadoc for why — in short,
+     * {@link #hasAsyncQuestion} keeps a target BUSY, so no second task can reach this state, for as
+     * long as an earlier one's {@code turnId} is still stamped). That is an emergent guarantee from
+     * two other facts, not one this method enforces, so this branch stays in as defence in depth
+     * rather than being removed as dead code: if it ever weakens, returning whichever candidate a
+     * {@code ConcurrentHashMap} iteration reaches first would let a genuine reply complete the
+     * <em>wrong</em> ticket — silently handing the lead something that reads like a correct answer to
+     * a delegation the worker never touched, which is worse than a failure because the lead acts on
+     * it. When more than one candidate exists, guessing is not safe: fall back to the inbox exactly
+     * as the zero-candidate case does, and let {@link #abandon} apply the eventual recovery
+     * deterministically instead.
+     *
      * @return always {@code true} — the reply resolved a live send, completed a parked ticket, or
      *         was queued
      */
@@ -392,13 +413,21 @@ public final class MessageService {
         // FAILED with a misleading "session released before it replied" reason, even though the reply
         // had, in fact, arrived. Completing the matching ticket directly here means fleet_poll{ticket}
         // sees the real reply instead.
-        Task orphan = askAnsweredAsyncTask(session);
-        if (orphan != null && orphan.future.complete(new Reply(Outcome.REPLIED, content))) {
-            if (orphan.turnId != null) {
-                asyncTasksByTurn.remove(orphan.turnId, orphan);
+        List<Task> candidates = askAnsweredAsyncTasks(session);
+        if (candidates.size() == 1) {
+            Task orphan = candidates.get(0);
+            if (orphan.future.complete(new Reply(Outcome.REPLIED, content))) {
+                if (orphan.turnId != null) {
+                    asyncTasksByTurn.remove(orphan.turnId, orphan);
+                }
+                count(FleetMetrics.REPLIES, "path", "async-recovered");
+                return true;                   // the ticket itself took it — no inbox stranding at all
             }
-            count(FleetMetrics.REPLIES, "path", "async-recovered");
-            return true;                       // the ticket itself took it — no inbox stranding at all
+        } else if (candidates.size() > 1) {
+            List<String> tickets = candidates.stream().map(t -> t.ticket).toList();
+            log.warn("reply from {} matches {} open async tickets {} — cannot tell which one it "
+                    + "answers, queuing to the inbox instead of guessing", session, candidates.size(),
+                    tickets);
         }
         inbox.publish(session, UUID.randomUUID().toString(), content);
         // CB-640: record the stranding itself (not just the reply text) so fleet health can see a
@@ -414,21 +443,38 @@ public final class MessageService {
     }
 
     /**
-     * The still-open async task on {@code target} whose {@code fleet_ask} was already answered — its
-     * {@link Task#turnId} is stamped but its {@link Task#question} was cleared by {@link #answer} —
-     * yet whose future is not resolved yet (#137). {@code null} if no such task exists, including the
+     * Every still-open async task on {@code target} whose {@code fleet_ask} was already answered —
+     * its {@link Task#turnId} is stamped but its {@link Task#question} was cleared by {@link #answer}
+     * — yet whose future is not resolved yet (#137). Empty if no such task exists, including the
      * common case where {@code target}'s worker never used {@code fleet_ask} at all (a task that was
      * never asked has {@code turnId == null}, so it can never match here and only ever completes
      * through the ordinary rendezvous fast path in {@link #reply}).
+     *
+     * <p><strong>Returns at most one entry today — verified, not assumed.</strong> {@link #send}
+     * refuses to open a waiter on {@code target} while {@link #hasAsyncQuestion} is true, and that
+     * check matches ANY task whose {@code turnId} is still stamped in {@code asyncTasksByTurn} —
+     * not only while its question is still open. {@link #answer} deliberately leaves that stamp in
+     * place ({@code clearAsyncQuestion(turnId, false)}) until the resumed turn's own future actually
+     * resolves, at which point {@link #finishAsyncTask} both removes the stamp AND completes that
+     * task's future in the same call. So a second task can never reach "{@code turnId} stamped, future
+     * still open" — the exact pair this method matches on — while a first one already holds it: by
+     * the time the stamp is gone, so is the eligibility. This is an emergent property of those two
+     * facts holding together, not something this method (or its callers) enforces on its own — flip
+     * {@code forgetTurn} to {@code true} in that one {@link #answer} call and it silently stops being
+     * true, with nothing left to fail loudly. The callers below still handle "more than one" as
+     * defence in depth against exactly that, not because they exercise it today: {@link #reply}
+     * treats it as unresolvable and falls back to the inbox; {@link #abandon} would pick the oldest
+     * deterministically (its own {@code matching} list has no such guarantee — see its javadoc).
      */
-    private Task askAnsweredAsyncTask(String target) {
+    private List<Task> askAnsweredAsyncTasks(String target) {
+        List<Task> candidates = new ArrayList<>();
         for (Task task : tasks.values()) {
             if (target.equals(task.target) && task.question == null && task.turnId != null
                     && !task.future.isDone()) {
-                return task;
+                candidates.add(task);
             }
         }
-        return null;
+        return candidates;
     }
 
     /** Record a counter sample when a registry is wired; a no-op in unit tests. */
@@ -473,16 +519,63 @@ public final class MessageService {
      * outcome is counted, so a torn-down delegation stops being invisible to {@code /metrics}.
      *
      * <p><strong>#137 defence in depth.</strong> {@link #reply} already hands a worker's real
-     * {@code fleet_reply} straight to the async ticket it belongs to whenever one is still parked
-     * waiting for it (see {@link #askAnsweredAsyncTask}), so by the time a session is released its
-     * tasks are normally already resolved — this loop's {@code complete} calls are then harmless
-     * no-ops (a {@link CompletableFuture} can only resolve once). But should some other path someday
-     * strand a reply in the inbox without completing its ticket, checking
+     * {@code fleet_reply} straight to the async ticket it belongs to whenever exactly one is still
+     * parked waiting for it (see {@link #askAnsweredAsyncTasks}), so by the time a session is
+     * released its tasks are normally already resolved — this loop's {@code complete} calls are then
+     * harmless no-ops (a {@link CompletableFuture} can only resolve once). But should some other path
+     * someday strand a reply in the inbox without completing its ticket, checking
      * {@link #hasStrandedReply(String)} here — before ever writing a failure — means a torn-down
      * session whose worker in fact replied is still reported {@code REPLIED} with that reply's own
      * text, never the misleading "the worker session was released before it replied" (which also
      * means the snapshot/worktree recovery hint that follows it never prints once a reply exists).
      *
+     * <p><strong>At most one task gets the recovered reply — and here, unlike {@link #reply}'s
+     * {@link #askAnsweredAsyncTasks}, {@code matching.size() >= 2} alone is reachable today.</strong>
+     * This method's {@code matching} filter has no {@code turnId != null} requirement, so it matches
+     * any plain (never-asked) open task too — and {@link #sendAsync} does not limit a target to one
+     * of those: a second {@code fleet_send{wait:false}} at a target that is still busy returns its own
+     * ticket immediately and simply parks its {@link #send} behind the target's session lock for up
+     * to {@link #ASYNC_TIMEOUT_MS}, exactly as {@code abandonFailsEveryPendingAsyncTicketForTheReleasedTarget}
+     * already proves. Before this fix, the loop below drained the strand once and then reused that
+     * same {@code Reply} for <em>every</em> task it walked past — so two open tasks really did both
+     * complete {@code REPLIED} with the same text (see the pre-fix loop in commit 97f6c33's parent).
+     * A stranded reply is one worker answer, so it can settle at most one open task on this target —
+     * never every open task, and never a guess. When more than one task is still open here, the
+     * recovered reply goes to the <em>oldest</em> (lowest {@link Task#createdNanos}) — it has been
+     * waiting longest, so it is the one most likely to be what the reply actually answers. Every
+     * other open task keeps the ordinary {@code WORKER_FAILED} path it would take without a stranded
+     * reply at all.
+     *
+     * <p><strong>{@code matching.size() >= 2} together with {@code hadStrandedReply} is a different
+     * question, and today it is defence in depth rather than a path this codebase's public API can
+     * drive.</strong> This class has exactly two sites that ever acquire a target's entry in
+     * {@code sessionLocks} — {@link #send} and {@link #answer} — and both open a {@link Rendezvous}
+     * waiter for that same target as the very first thing they do after acquiring the lock, then hold
+     * lock and waiter together for the rest of their critical section ({@link #send} also clears
+     * {@link #strandedReplies} right there, the instant it opens its waiter — before it ever enqueues
+     * delivery). So "the session lock is held" and "a live waiter is open for it" are the same fact
+     * throughout this class, and {@link #reply}'s fast path always resolves a currently-open waiter
+     * directly rather than stranding. The two facts this method wants therefore cannot be produced
+     * side by side: while the lock is held, a real reply resolves the open waiter directly and never
+     * reaches {@link #strandedReplies}; the instant the lock is free, any parked matching task's own
+     * {@link #send} that is scheduled next wins it and, by opening its waiter, clears the strand again
+     * before this method ever runs. There is no way to hold that lock open-but-unaccepted from outside
+     * {@link #send}/{@link #answer} to freeze a window in between. Constructing both facts at once
+     * through {@code sendAsync}/{@code reply}/{@code ask}/{@code answer} would need a race against
+     * virtual-thread scheduling, not a deterministic sequence — so the oldest-wins code below stays as
+     * defence in depth against a regression to that mechanism (e.g. clearing {@link #strandedReplies}
+     * on a narrower condition than "any acceptance"), not because today's test suite exercises the
+     * conjunction. {@code matching.size() >= 2} alone, without a strand, is exactly what
+     * {@code abandonFailsEveryPendingAsyncTicketForTheReleasedTarget} already covers.
+     *
+     * <p><strong>Do not "fix" that gap with a test that reaches past this class.</strong> A test can
+     * build both facts by calling {@link Rendezvous#close} itself on the waiter an accepted
+     * {@link #send} is still blocked on: the send keeps the lock, no waiter is registered any more, a
+     * second parked task stays open, and the next {@link #reply} then strands. That was checked, and
+     * such a test does go red against the pre-fix loop. But it only goes red because it broke the
+     * lock-and-waiter invariant above from outside — no caller of this class ever does that — so it
+     * pins a state production cannot reach, and would read to the next person as if it could.
+     *
      * @return true if a live waiter or an async task was failed (never true for one recovered as a
      *         reply — see the note above)
      */
@@ -494,21 +587,39 @@ public final class MessageService {
         CompletableFuture<Rendezvous.Resolution> waiter = rendezvous.currentWaiter(target);
         boolean failed = waiter != null && !waiter.isDone() && rendezvous.resolveFailure(waiter, reason);
         boolean asyncFailed = false;
-        Reply recovered = null; // lazily drained at most once, only if a task actually needs it
+
+        List<Task> matching = new ArrayList<>();
         for (Task task : tasks.values()) {
-            if (!target.equals(task.target) || task.question != null || task.future.isDone()) {
-                continue;
+            if (target.equals(task.target) && task.question == null && !task.future.isDone()) {
+                matching.add(task);
             }
-            if (hadStrandedReply && recovered == null) {
-                recovered = recoverStrandedReply(target);
+        }
+        Task recoveryTask = null;
+        if (hadStrandedReply && !matching.isEmpty()) {
+            recoveryTask = matching.get(0);
+            for (Task candidate : matching) {
+                if (candidate.createdNanos < recoveryTask.createdNanos) {
+                    recoveryTask = candidate;
+                }
             }
-            Reply outcome = recovered != null ? recovered : new Reply(Outcome.WORKER_FAILED, reason);
+        }
+        Reply recovered = recoveryTask != null ? recoverStrandedReply(target) : null;
+        for (Task task : matching) {
+            boolean isRecovery = task == recoveryTask && recovered != null;
+            Reply outcome = isRecovery ? recovered : new Reply(Outcome.WORKER_FAILED, reason);
             if (task.future.complete(outcome)) {
                 if (outcome.outcome() == Outcome.WORKER_FAILED) {
                     asyncFailed = true;
                 } else if (task.turnId != null) {
                     asyncTasksByTurn.remove(task.turnId, task);
                 }
+            } else if (isRecovery) {
+                // The recovered reply was already drained out of the inbox, but this task resolved
+                // through another path (e.g. a concurrent reply() or a second abandon() racing this
+                // one) between us choosing it and completing it here. Put the reply back rather than
+                // lose it silently — it may still belong to some other still-open task, or the next
+                // caller that drains this target's inbox.
+                inbox.publish(target, UUID.randomUUID().toString(), recovered.text());
             }
         }
         if (failed) {
@@ -523,6 +634,10 @@ public final class MessageService {
      * stranding fact raced away, e.g. a lead's own {@code fleet_poll} on the raw session already
      * drained it first). When more than one message is queued, only the newest is the worker's actual
      * final answer ({@link #drainReplies} returns them oldest-first).
+     *
+     * <p>This does drain (removes the messages from the inbox) before the caller knows whether the
+     * task it is recovering for will actually accept them — {@link #abandon} is the one that puts a
+     * reply back if its {@code complete} call turns out to lose the race.
      */
     private Reply recoverStrandedReply(String target) {
         var messages = drainReplies(target);

fleetd/src/main/java/dev/ltms/fleet/rest/FleetApp.java

@@ -321,6 +321,12 @@ public final class FleetApp {
                 .map(s -> SessionManager.rosterView(s, live.get(s.terminalId())))
                 .toList();
         Map<String, Object> body = new LinkedHashMap<>();
+        // fleetd #199: the endpoint became /members in the CB-634 rename but the body key stayed
+        // "workers", so a caller that read "members" saw an empty fleet and reported no members at
+        // all. "members" is the canonical key; "workers" stays as a deprecated alias so an existing
+        // REST consumer keeps working — the out-of-band path a lead falls back to when its MCP mount
+        // drops reads this endpoint. Drop the alias once nothing reads it.
+        body.put("members", out);
         body.put("workers", out);
         // CB-586: operator visibility for the refs/wip snapshot store without shelling into the
         // repo — how many snapshot refs exist and roughly what they cost. Present only once a

fleetd/src/test/java/dev/ltms/fleet/member/HerdrPeerLauncherAllowListWiringTest.java

@@ -12,20 +12,26 @@ import dev.ltms.fleet.peer.Capability;
 import dev.ltms.fleet.peer.MemberRole;
 import dev.ltms.fleet.peer.SpawnRequest;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
 import org.slf4j.LoggerFactory;
 
+import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.attribute.PosixFileAttributeView;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Function;
 import java.util.function.Supplier;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assumptions.assumeTrue;
 
 /**
  * CB-633: proves the allow-list scrub is actually WIRED INTO the spawn path — not merely that its
@@ -119,6 +125,18 @@ class HerdrPeerLauncherAllowListWiringTest {
                 FleetConfig.MemberCredentials.POLICY_ALLOW_LIST, allow, List.of(), null);
     }
 
+    /**
+     * Same as {@link #allowList()} but with an operator-configured {@code known:} list, so the
+     * fallback overlay (the non-zsh / no-memberLoginShell path) has something visible to shadow —
+     * {@link FleetConfig.MemberCredentials#blockedSet()} is {@code known - allow}, so an empty
+     * {@code known} (what {@link #allowList()} uses) blocks nothing and a fallback test would have
+     * no sentinel entry to assert on.
+     */
+    private static Supplier<FleetConfig.MemberCredentials> allowListWithKnown(List<String> known) {
+        return () -> new FleetConfig.MemberCredentials(
+                FleetConfig.MemberCredentials.POLICY_ALLOW_LIST, List.of(), known, null);
+    }
+
     /**
      * CB-633 follow-up: a name that lives ONLY in {@code memberCredentials.allow:} — no profile
      * mentions it — must survive the scrub the real spawn path generates. Calling {@code
@@ -257,6 +275,268 @@ class HerdrPeerLauncherAllowListWiringTest {
                         + appender.list.stream().map(ILoggingEvent::getFormattedMessage).toList());
     }
 
+    /**
+     * fleetd #185 stage 2 pin: with {@code memberHerdrSocket:} absent (today's only mode, and the
+     * default — this host runs no other), the gap detector's WARN/INFO conclusions read exactly as
+     * they did before this fix. Real path: {@code FLEETD_WORKER_TOKEN} (the test profile's own
+     * {@code tokenEnv}) is a name the derived allow-list keeps, so it gets the "UNBLOCKED" WARN;
+     * {@code SOME_UNKNOWN_SECRET_TOKEN} is not derived from anywhere, so it gets the "scrub blanks
+     * them" INFO. This is the exact shape #185 stage 2 must not touch on this path.
+     */
+    @Test
+    void gapConclusionsAreByteIdenticalWhenMemberHerdrSocketIsAbsent() {
+        FakeHerdr herdr = new FakeHerdr();
+        Set<String> hostEnvNames = Set.of("FLEETD_WORKER_TOKEN", "SOME_UNKNOWN_SECRET_TOKEN");
+        WiringLauncher launcher = new WiringLauncher(herdr, allowList(), "/bin/zsh", () -> hostEnvNames,
+                () -> config(null));
+
+        List<String> messages = spawnAndCaptureLogs(launcher);
+
+        assertTrue(messages.contains("memberCredentials gap: 1 credential-shaped env var name(s) are on "
+                        + "neither known: nor allow: — the derived allow-list keeps them anyway (a "
+                        + "profile's gitTokenEnv/gitHostEnv/tokenEnv/env: names one, or this spawn "
+                        + "injects it), so every member pane inherits them UNBLOCKED — [FLEETD_WORKER_TOKEN]. "
+                        + "Add each to memberCredentials.known (or .allow if a member legitimately needs "
+                        + "it), or remove it from whatever profile setting derives it in."),
+                "expected the pre-existing UNBLOCKED WARN unchanged, got: " + messages);
+        assertTrue(messages.contains("memberCredentials gap: 1 credential-shaped env var name(s) are on "
+                        + "neither known: nor allow: — [SOME_UNKNOWN_SECRET_TOKEN]. The allow-list scrub "
+                        + "blanks them anyway (they are not on the derived allow-list), so no member pane "
+                        + "keeps them; add each to memberCredentials.known or .allow to make that explicit."),
+                "expected the pre-existing 'scrub blanks them' INFO unchanged, got: " + messages);
+    }
+
+    /**
+     * fleetd #185 stage 2: with {@code memberHerdrSocket:} configured, member panes run under a
+     * different OS user — {@link HerdrPeerLauncher#hostEnvNames} describes fleetd's own process, not
+     * that user's. Neither "inherits them UNBLOCKED" nor "scrub blanks them" is evidence-backed
+     * there, so neither may print; the single unknown-environment WARN must, naming the config key.
+     */
+    @Test
+    void gapDetectorReportsUnknownInsteadOfAConclusionWhenMemberHerdrSocketIsConfigured() {
+        FakeHerdr herdr = new FakeHerdr();
+        Set<String> hostEnvNames = Set.of("FLEETD_WORKER_TOKEN", "SOME_UNKNOWN_SECRET_TOKEN");
+        WiringLauncher launcher = new WiringLauncher(herdr, allowList(), "/bin/zsh", () -> hostEnvNames,
+                () -> configWithMemberHerdrSocket("/tmp/other-user-herdr.sock"));
+
+        List<String> messages = spawnAndCaptureLogs(launcher);
+
+        assertTrue(messages.stream().anyMatch(m -> m.contains("memberHerdrSocket")
+                        && m.contains("UNKNOWN") && m.contains("cannot be verified")),
+                "expected the unknown-member-environment WARN naming memberHerdrSocket, got: " + messages);
+        assertFalse(messages.stream().anyMatch(m -> m.contains("UNBLOCKED")),
+                "the 'inherits them UNBLOCKED' conclusion must not print once the evidence is about "
+                        + "the wrong (daemon's own) environment — got: " + messages);
+        assertFalse(messages.stream().anyMatch(m -> m.contains("scrub blanks them")),
+                "the 'scrub blanks them' conclusion must not print once the evidence is about the "
+                        + "wrong (daemon's own) environment — got: " + messages);
+    }
+
+    /**
+     * fleetd #185 stage 2: the unknown-environment WARN is a standing fact about this launcher's
+     * configuration, not per-spawn news — it must fire once per launcher instance, the same shape as
+     * every other one-time WARN in this class (e.g. {@code warnNonZsh}).
+     */
+    @Test
+    void theUnknownEnvironmentWarnFiresOnceNotOncePerSpawn() {
+        FakeHerdr herdr = new FakeHerdr();
+        Set<String> hostEnvNames = Set.of("FLEETD_WORKER_TOKEN", "SOME_UNKNOWN_SECRET_TOKEN");
+        WiringLauncher launcher = new WiringLauncher(herdr, allowList(), "/bin/zsh", () -> hostEnvNames,
+                () -> configWithMemberHerdrSocket("/tmp/other-user-herdr.sock"));
+
+        Logger logger = (Logger) LoggerFactory.getLogger(HerdrPeerLauncher.class);
+        Level original = logger.getLevel();
+        logger.setLevel(Level.WARN);
+        ListAppender<ILoggingEvent> appender = new ListAppender<>();
+        appender.start();
+        logger.addAppender(appender);
+        try {
+            launcher.spawn(new SpawnRequest("test", null, null, null, null, MemberRole.DEV));
+            launcher.spawn(new SpawnRequest("test", null, null, null, null, MemberRole.DEV));
+        } finally {
+            logger.detachAppender(appender);
+            logger.setLevel(original);
+        }
+
+        long count = appender.list.stream()
+                .filter(e -> e.getFormattedMessage().contains("cannot be verified from here"))
+                .count();
+        assertEquals(1, count, "the unknown-member-environment WARN must fire once per launcher "
+                + "instance, not once per spawn — got " + count + " occurrence(s) among: "
+                + appender.list.stream().map(ILoggingEvent::getFormattedMessage).toList());
+    }
+
+    /**
+     * Hard constraint: the gap detector must never log an env var VALUE, only its NAME. {@code
+     * SOME_UNKNOWN_SECRET_TOKEN} resolves to a distinctive canary value through the same {@code env}
+     * lookup the launcher uses elsewhere (SHELL, PATH, token resolution) — proving the value IS
+     * resolvable does not mean the detector reads it, since {@link HerdrPeerLauncher#hostEnvNames}
+     * (names only) is its data source, never {@code env.apply(name)} for those names.
+     */
+    @Test
+    void theGapDetectorNeverLogsAnEnvVarValueOnlyItsName() {
+        FakeHerdr herdr = new FakeHerdr();
+        String canary = "sekrit-value-CANARY-9f3a1b7c";
+        Set<String> hostEnvNames = Set.of("FLEETD_WORKER_TOKEN", "SOME_UNKNOWN_SECRET_TOKEN");
+        WiringLauncher launcher = new WiringLauncher(herdr, allowList(), "/bin/zsh", () -> hostEnvNames,
+                () -> config(null), Map.of("SOME_UNKNOWN_SECRET_TOKEN", canary));
+
+        List<String> messages = spawnAndCaptureLogs(launcher);
+
+        assertTrue(messages.stream().anyMatch(m -> m.contains("SOME_UNKNOWN_SECRET_TOKEN")),
+                "expected the credential-shaped NAME to appear in the log, got: " + messages);
+        assertFalse(messages.stream().anyMatch(m -> m.contains(canary)),
+                "the log must never contain an env var VALUE, only its NAME — got: " + messages);
+    }
+
+    /**
+     * fleetd #213 defect 1, acceptance criterion 1: {@code memberHerdrSocket} configured and {@code
+     * memberLoginShell} configured as non-zsh must fall back to the sentinel overlay exactly like a
+     * non-zsh {@code $SHELL} does today — and the "generated ZDOTDIR" INFO must not appear, since no
+     * scrub actually runs. The WiringLauncher's own {@code env("SHELL")} is deliberately set to
+     * {@code /bin/zsh} — the OPPOSITE of what {@code memberLoginShell} says — so a launcher that
+     * (incorrectly) fell back to fleetd's own {@code $SHELL} here would wrongly pass the gate and
+     * fail this test.
+     */
+    @Test
+    void memberHerdrSocketWithNonZshMemberLoginShellFallsBackToTheOverlay() {
+        FakeHerdr herdr = new FakeHerdr();
+        WiringLauncher launcher = new WiringLauncher(herdr, allowListWithKnown(List.of("SOME_TOKEN")),
+                "/bin/zsh", null,
+                () -> configWithMemberHerdrSocket("/tmp/other-user-herdr.sock", "/bin/bash"));
+
+        List<String> messages = spawnAndCaptureLogs(launcher);
+
+        assertEquals("blocked-by-fleetd-cb596-see-gitea-issue-82", launcher.env.get("SOME_TOKEN"),
+                "a non-zsh memberLoginShell must fall back to the CB-596 sentinel overlay, exactly "
+                        + "like a non-zsh $SHELL does when memberHerdrSocket is absent");
+        assertFalse(launcher.env.containsKey("ZDOTDIR"),
+                "no scrub directory may be generated when the configured member login shell is not zsh");
+        assertFalse(messages.stream().anyMatch(m -> m.contains("generated ZDOTDIR")),
+                "the 'generated ZDOTDIR' INFO must not appear when the scrub never runs — got: " + messages);
+    }
+
+    /**
+     * fleetd #213 defect 1, acceptance criterion 2: {@code memberHerdrSocket} configured and NO
+     * {@code memberLoginShell} configured must fall back exactly like criterion 1 above — AND
+     * fleetd's own {@code $SHELL} must never even be consulted (not merely "not decisive"). The
+     * fixture's {@code env} function reports {@code /bin/zsh} for {@code SHELL} — a value that would
+     * WRONGLY pass the zsh gate if the fix regressed to reading it — while flagging whether it was
+     * ever asked for at all, so this test fails loudly on either kind of regression.
+     */
+    @Test
+    void memberHerdrSocketWithNoMemberLoginShellFallsBackAndNeverConsultsFleetdsOwnShell() {
+        FakeHerdr herdr = new FakeHerdr();
+        AtomicBoolean shellQueried = new AtomicBoolean(false);
+        Function<String, String> env = name -> {
+            if ("SHELL".equals(name)) {
+                shellQueried.set(true);
+                return "/bin/zsh"; // would wrongly pass the zsh gate if this ever leaked through
+            }
+            return null;
+        };
+        WiringLauncher launcher = new WiringLauncher(herdr, allowListWithKnown(List.of("SOME_TOKEN")), env,
+                () -> configWithMemberHerdrSocket("/tmp/other-user-herdr.sock", null));
+
+        List<String> messages = spawnAndCaptureLogs(launcher);
+
+        assertFalse(shellQueried.get(), "fleetd's own $SHELL must never be consulted once "
+                + "memberHerdrSocket is configured — only memberLoginShell: may decide the gate");
+        assertEquals("blocked-by-fleetd-cb596-see-gitea-issue-82", launcher.env.get("SOME_TOKEN"),
+                "no memberLoginShell configured must fall back to the sentinel overlay, same as a "
+                        + "configured non-zsh shell");
+        assertFalse(messages.stream().anyMatch(m -> m.contains("generated ZDOTDIR")),
+                "no scrub may run without a configured memberLoginShell — got: " + messages);
+    }
+
+    /**
+     * fleetd #213 defect 2, acceptance criterion 3: with {@code memberHerdrSocket} configured, a
+     * zsh {@code memberLoginShell}, and {@code worktreeRoot}/{@code worktreeGroup} both configured,
+     * the generated scrub directory must live under {@code worktreeRoot} — NEVER under {@code
+     * java.io.tmpdir}, which is fleetd's own 0700 temp dir and unreadable by the member's different
+     * OS user. {@code worktreeGroup} is set to the CURRENT process's own primary group so {@code
+     * EnvAllowListScrub}'s group-sharing step resolves on whatever host runs this test, rather than
+     * hardcoding a group name that may not exist here.
+     */
+    @Test
+    void memberHerdrSocketWithZshMemberLoginShellPutsTheScrubOutsideJavaIoTmpdir(@TempDir Path worktreeRoot)
+            throws IOException {
+        String group = currentUserGroup();
+        FakeHerdr herdr = new FakeHerdr();
+        WiringLauncher launcher = new WiringLauncher(herdr, allowList(), "/bin/bash-should-be-ignored", null,
+                () -> configWithMemberHerdrSocketRootAndGroup("/tmp/other-user-herdr.sock", "/bin/zsh",
+                        worktreeRoot.toString(), group));
+
+        launcher.spawn(new SpawnRequest("test", null, null, null, null, MemberRole.DEV));
+
+        String zdotdir = launcher.env.get("ZDOTDIR");
+        assertNotNull(zdotdir, "a zsh memberLoginShell with worktreeRoot+worktreeGroup configured "
+                + "must still generate a ZDOTDIR");
+        Path dir = Path.of(zdotdir);
+        // The immediate PARENT is asserted (not merely startsWith(java.io.tmpdir)), because a
+        // JUnit @TempDir is itself carved out of the JVM's java.io.tmpdir — startsWith alone would
+        // pass by coincidence of the test fixture, not because the launcher used worktreeRoot.
+        assertEquals(worktreeRoot.toAbsolutePath().normalize(), dir.getParent(),
+                "the generated scrub directory's parent must be the configured worktreeRoot, not "
+                        + "System.getProperty(\"java.io.tmpdir\") — got parent " + dir.getParent());
+    }
+
+    /**
+     * fleetd #213, acceptance criterion 4: with {@code memberHerdrSocket} absent (today's only
+     * mode), behaviour must be byte-identical to before this fix — fleetd's own {@code $SHELL}
+     * still decides the gate (proven here, not merely assumed, by flagging the lookup), and the
+     * scrub still lands under {@code java.io.tmpdir}.
+     */
+    @Test
+    void memberHerdrSocketAbsentStillConsultsFleetdsOwnShellAndBehavesAsBefore() {
+        FakeHerdr herdr = new FakeHerdr();
+        AtomicBoolean shellQueried = new AtomicBoolean(false);
+        Function<String, String> env = name -> {
+            if ("SHELL".equals(name)) {
+                shellQueried.set(true);
+                return "/bin/zsh";
+            }
+            return null;
+        };
+        WiringLauncher launcher = new WiringLauncher(herdr, allowList(), env, null); // memberHerdrSocket absent
+
+        launcher.spawn(new SpawnRequest("test", null, null, null, null, MemberRole.DEV));
+
+        assertTrue(shellQueried.get(), "with memberHerdrSocket absent, fleetd's own $SHELL must "
+                + "still decide the zsh gate, unchanged from before this fix");
+        String zdotdir = launcher.env.get("ZDOTDIR");
+        assertNotNull(zdotdir, "SHELL=/bin/zsh with memberHerdrSocket absent must still generate a "
+                + "ZDOTDIR, as before this fix");
+        Path dir = Path.of(zdotdir);
+        assertTrue(dir.startsWith(Path.of(System.getProperty("java.io.tmpdir"))),
+                "with memberHerdrSocket absent the scrub directory must still be generated under "
+                        + "java.io.tmpdir, unchanged from before this fix: " + dir);
+    }
+
+    /** The current process's own primary group — resolvable on whatever host runs this test. */
+    private static String currentUserGroup() throws IOException {
+        PosixFileAttributeView view = Files.getFileAttributeView(Path.of("."), PosixFileAttributeView.class);
+        assumeTrue(view != null, "this host's filesystem does not support POSIX group ownership");
+        return view.readAttributes().group().getName();
+    }
+
+    /** Spawn once through the real launcher path, capturing every INFO+ line this class logs. */
+    private static List<String> spawnAndCaptureLogs(HerdrPeerLauncher launcher) {
+        Logger logger = (Logger) LoggerFactory.getLogger(HerdrPeerLauncher.class);
+        Level original = logger.getLevel();
+        logger.setLevel(Level.INFO);
+        ListAppender<ILoggingEvent> appender = new ListAppender<>();
+        appender.start();
+        logger.addAppender(appender);
+        try {
+            launcher.spawn(new SpawnRequest("test", null, null, null, null, MemberRole.DEV));
+        } finally {
+            logger.detachAppender(appender);
+            logger.setLevel(original);
+        }
+        return appender.list.stream().map(ILoggingEvent::getFormattedMessage).toList();
+    }
+
     private static String readAll(Path p) {
         try {
             return Files.readString(p);
@@ -294,12 +574,40 @@ class HerdrPeerLauncherAllowListWiringTest {
 
         WiringLauncher(FakeHerdr herdr, Supplier<FleetConfig.MemberCredentials> creds, String shell,
                        Supplier<Set<String>> hostEnvNames, Supplier<FleetConfig> config) {
+            this(herdr, creds, shell, hostEnvNames, config, Map.of());
+        }
+
+        /**
+         * Plus a host-env value map (name → value), resolved through the same {@code env} lookup
+         * every adapter uses for {@code SHELL}/{@code PATH}/token resolution — fleetd #185 stage 2's
+         * "the gap detector never logs a value" tests use this to prove a value that IS resolvable
+         * for a credential-shaped name never reaches the log, since the detector only ever reads
+         * {@code hostEnvNames} (names), never {@code env.apply(name)} (values), for those names.
+         */
+        WiringLauncher(FakeHerdr herdr, Supplier<FleetConfig.MemberCredentials> creds, String shell,
+                       Supplier<Set<String>> hostEnvNames, Supplier<FleetConfig> config,
+                       Map<String, String> extraEnvValues) {
             super("test", new AgentControl(herdr), new WorkspaceControl(herdr),
                     Map.of("test", profile()), "test",
-                    name -> "SHELL".equals(name) ? shell : null,
+                    name -> "SHELL".equals(name) ? shell
+                            : (extraEnvValues != null && extraEnvValues.containsKey(name))
+                                    ? extraEnvValues.get(name) : null,
                     0, () -> 0L, () -> { }, null, creds, hostEnvNames, config);
         }
 
+        /**
+         * Full control over the {@code env} lookup, bypassing the {@code shell}/{@code
+         * extraEnvValues} convenience above entirely — fleetd #213's "fleetd's own $SHELL must
+         * never be consulted" tests need to OBSERVE whether {@code SHELL} was ever looked up, which
+         * a plain value substitution cannot do.
+         */
+        WiringLauncher(FakeHerdr herdr, Supplier<FleetConfig.MemberCredentials> creds,
+                       Function<String, String> env, Supplier<FleetConfig> config) {
+            super("test", new AgentControl(herdr), new WorkspaceControl(herdr),
+                    Map.of("test", profile()), "test",
+                    env, 0, () -> 0L, () -> { }, null, creds, null, config);
+        }
+
         @Override
         protected Launch buildLaunch(FleetConfig.Profile cfg, LaunchSpec spec) {
             Map<String, String> launchEnv = baseEnv(cfg);
@@ -321,6 +629,82 @@ class HerdrPeerLauncherAllowListWiringTest {
                 null, null, null, null, null).withDefaults();
     }
 
+    /**
+     * fleetd #185 stage 2: a config with {@code memberHerdrSocket:} set — member panes run on a
+     * second herdr owned by a different OS user, so {@link HerdrPeerLauncher#hostEnvNames} no
+     * longer describes what a member pane inherits.
+     */
+    private static FleetConfig configWithMemberHerdrSocket(String memberHerdrSocket) {
+        return new FleetConfig(null, null, memberHerdrSocket, Map.of(), null, null, null, null, null,
+                null, null, null, null, null, null, null, null, null, null, null).withDefaults();
+    }
+
+    /**
+     * fleetd #213: as {@link #configWithMemberHerdrSocket(String)}, plus the {@code
+     * memberLoginShell:} the member's OS user actually runs — the config key {@link
+     * HerdrPeerLauncher#applyEnvironmentAllowListPolicy} must consult instead of fleetd's own
+     * {@code $SHELL} once {@code memberHerdrSocket} is configured.
+     */
+    private static FleetConfig configWithMemberHerdrSocket(String memberHerdrSocket, String memberLoginShell) {
+        return new FleetConfig(
+                null,               // bind
+                null,               // herdrSocket
+                memberHerdrSocket,  // memberHerdrSocket
+                Map.of(),           // profiles
+                null,               // guard
+                null,               // worktreeRoot
+                null,               // lifecycle
+                null,               // spawnReadyTimeoutMs
+                null,               // spawnReadyPollMs
+                null,               // broker
+                null,               // primary
+                null,               // fleet
+                null,               // leadHeartbeat
+                null,               // health
+                null,               // placement
+                null,               // auth
+                null,               // configReload
+                null,               // quarantineCooldownSeconds
+                null,               // memberCredentials
+                null,               // coordinator
+                null,               // worktreeGroup
+                memberLoginShell    // memberLoginShell
+        ).withDefaults();
+    }
+
+    /**
+     * fleetd #213: as above, plus {@code worktreeRoot:}/{@code worktreeGroup:} — both required for
+     * the ZDOTDIR scrub to run at all once {@code memberHerdrSocket} is configured; either missing
+     * falls back to the sentinel overlay, same as a non-zsh {@code memberLoginShell}.
+     */
+    private static FleetConfig configWithMemberHerdrSocketRootAndGroup(String memberHerdrSocket,
+            String memberLoginShell, String worktreeRoot, String worktreeGroup) {
+        return new FleetConfig(
+                null,               // bind
+                null,               // herdrSocket
+                memberHerdrSocket,  // memberHerdrSocket
+                Map.of(),           // profiles
+                null,               // guard
+                worktreeRoot,       // worktreeRoot
+                null,               // lifecycle
+                null,               // spawnReadyTimeoutMs
+                null,               // spawnReadyPollMs
+                null,               // broker
+                null,               // primary
+                null,               // fleet
+                null,               // leadHeartbeat
+                null,               // health
+                null,               // placement
+                null,               // auth
+                null,               // configReload
+                null,               // quarantineCooldownSeconds
+                null,               // memberCredentials
+                null,               // coordinator
+                worktreeGroup,      // worktreeGroup
+                memberLoginShell    // memberLoginShell
+        ).withDefaults();
+    }
+
     /** The generated directory is a temp directory; make sure the test does not leave a pile. */
     @Test
     void theGeneratedDirectoryIsRemovedWhenThePaneIsStopped() {

fleetd/src/test/java/dev/ltms/fleet/msg/MessageServiceTest.java

@@ -688,6 +688,32 @@ class MessageServiceTest {
         assertFailedTicket(third, "agent target term_a not found");
     }
 
+    // --- #137 follow-up: abandon() must not guess when more than one task is open ---------------
+    //
+    // A test combining a genuine stranded reply (hasStrandedReply(T)==true) with two simultaneously
+    // open matching tasks was attempted here and removed after investigation showed the combination
+    // is not reachable through the public API today, not merely hard to time right:
+    //
+    // This class has exactly two call sites that ever hold a target's entry in the session-lock map
+    // (send() and answer()), and both open a Rendezvous waiter for that same target as the first thing
+    // they do after acquiring the lock, holding lock and waiter together for their whole critical
+    // section. So "the lock is held" and "a live waiter is open" are the same fact throughout this
+    // class. reply()'s fast path always resolves a currently-open waiter directly instead of
+    // stranding — so a strand can only be created while NO task is accepted (lock free), and the
+    // instant the lock is next taken (by any parked matching task's own send(), the moment it is
+    // scheduled), that acceptance clears strandedReplies again (see send()'s CB-640 comment) before
+    // abandon() can ever observe both facts together. Confirmed empirically too: an earlier version of
+    // this test stranded a reply, then created an "accepted" task (awaitWaiting()) followed by a
+    // "parked" one — and the accepted task's own acceptance silently cleared the strand it was
+    // supposed to be racing against, so the parked task came back WORKER_FAILED instead of DONE, not
+    // because the fix was missing but because the test's premise could not be constructed.
+    //
+    // The reachable half — matching.size() >= 2 alone, no strand — is exactly what
+    // abandonFailsEveryPendingAsyncTicketForTheReleasedTarget already covers (all fail, none guess).
+    // The oldest-wins code in abandon() stays as defence in depth (see its own javadoc) against a
+    // regression that would make the conjunction reachable, e.g. clearing strandedReplies on a
+    // narrower condition than "any acceptance" — not because this suite exercises it today.
+
     @Test
     void abandonDoesNotFailAnAsyncTicketWaitingForAnAnswer() throws Exception {
         String ticket = messages.sendAsync(T, "task that asks");

fleetd/src/test/java/dev/ltms/fleet/rest/FleetAppTest.java

@@ -218,9 +218,17 @@ class FleetAppTest {
 
         HttpResponse<String> res = req(port, "GET", "/members");
         assertEquals(200, res.statusCode());
-        JsonNode workers = mapper.readTree(res.body()).get("workers");
-        assertEquals(1, workers.size());
-        JsonNode w = workers.get(0);
+        JsonNode body = mapper.readTree(res.body());
+        // fleetd #199: "members" is the canonical key. The endpoint is /members, so a caller that
+        // reads "members" must not see an empty fleet. "workers" is kept only as a deprecated alias
+        // and must carry the same rows — assert both, or the alias can silently drift.
+        JsonNode members = body.get("members");
+        assertNotNull(members, "GET /members must return its rows under \"members\"");
+        assertEquals(1, members.size());
+        JsonNode workers = body.get("workers");
+        assertNotNull(workers, "the deprecated \"workers\" alias is still emitted");
+        assertEquals(members, workers, "the alias must carry the same rows as \"members\"");
+        JsonNode w = members.get(0);
         assertEquals(spawned.get("terminalId").asText(), w.get("sessionId").asText());
         assertEquals(paneId, w.get("paneId").asText());
         assertEquals("ltms-local", w.get("profile").asText());