bridged/fleetd.example.yaml

@@ -505,20 +505,51 @@ guard:
 # through either: the daemon logs a WARN naming any credential-shaped env var it finds on neither
 # list (never its value), so a secret added to the store later does not go unnoticed forever.
 #
-#   policy → only "deny-by-default" exists today (an operator-authored deny-list was deliberately
-#            rejected — see above). An unrecognized value refuses to start, naming it.
-#   allow  → credential names a member legitimately needs. Left OUT of the pane's env overlay
-#            entirely, so the value the pane's own (login) shell exports passes through untouched.
-#   known  → every credential name the operator's store is known to export. Every name here NOT
-#            also in `allow` is overlaid with a non-secret sentinel value before the pane's login
-#            shell runs — real protection only for names the login shell does not itself re-export
-#            (see the ROUND-2 CORRECTION note above for the ones it does).
+#   policy → "deny-by-default" (the default; also accepted spelled "deny-list") overlays each
+#            known-but-not-allowed name BEFORE the pane's login shell runs — real protection only
+#            where that shell does not re-export the name (see ROUND-2 CORRECTION above). An
+#            unrecognized value refuses to start, naming it.
+#   policy → "allow-list" (CB-633) moves the control to a per-spawn ZDOTDIR directory the daemon
+#            generates and passes through tab.create's env map. Each generated startup file sources
+#            its ~/ counterpart FIRST and then runs the scrub, so the scrub happens after the
+#            operator's whole chain and no sourced file can undo it.
+#            The scrub is sourced from BOTH the generated .zshrc and the generated .zlogin, because
+#            herdr does not open the same kind of shell everywhere: macOS panes run a LOGIN zsh (so
+#            .zlogin runs), Linux panes run a plain interactive zsh (so .zlogin never runs at all).
+#            A scrub in .zlogin alone would be a control that silently does nothing on Linux.
+#            The allow-list is DERIVED, never typed:
+#            every profile's tokenEnv/gitTokenEnv/gitHostEnv values and env-map keys, plus an
+#            infrastructure set (PATH HOME SHELL TERM LANG LC_* TMPDIR USER LOGNAME PWD SHLVL EDITOR
+#            PAGER JAVA_HOME XDG_* ZDOTDIR), plus whatever keys this spawn's own env overlay carries.
+#            Adding a profile can therefore only widen the list, never break another spawn's scrub.
+#            Under this policy `known`/`allow` below become REPORTING ONLY — they feed the gap WARN,
+#            they are no longer a control. If the member's login shell is NOT zsh, the daemon logs a
+#            loud WARN saying protection is off and falls back to deny-by-default's overlay.
+#            Each pane writes a scrub-report.txt naming how many variables it kept of how many it
+#            saw; the daemon logs that "allowed N of M" line when the pane stops. If the report is
+#            MISSING the daemon logs a WARN instead — the scrub cannot then be confirmed to have
+#            run, and a silently-dead control is exactly what this policy exists to prevent.
+#   allow  → credential names a member legitimately needs. Under deny-by-default, left OUT of the
+#            pane's env overlay entirely, so the value the pane's own (login) shell exports passes
+#            through untouched. Under allow-list: reporting only.
+#   known  → every credential name the operator's store is known to export. Under deny-by-default,
+#            every name here NOT also in `allow` is overlaid with a non-secret sentinel value before
+#            the pane's login shell runs — real protection only for names that shell does not itself
+#            re-export (see the ROUND-2 CORRECTION note above). Under allow-list: reporting only.
+#   sshAuthSock → whether SSH_AUTH_SOCK may pass through under allow-list ("allow") or must be
+#            blanked like any other non-derived name ("block", the default). This is a decision you
+#            have to make explicitly: SSH_AUTH_SOCK is a handle to YOUR ssh-agent, and a member
+#            holding it can sign with your keys — it sits in no secret file and looks like no
+#            credential, which is why it slipped past three earlier tickets (gitea #110). Blocking
+#            it breaks git over SSH inside members (push/fetch authenticate as you); use HTTPS
+#            remotes or scoped deploy keys instead of allowing it lightly.
 #
 # HOT-RELOADABLE the same way `fleet:` is (CB-559): read fresh on every spawn, so editing this list
 # and reloading config (or restarting) changes what the NEXT spawn inherits; already-running members
 # are unaffected either way.
 # memberCredentials:
-#   policy: deny-by-default
+#   policy: deny-by-default        # or "deny-list", or "allow-list" (CB-633) — see above
+#   sshAuthSock: block             # allow-list only; see the sshAuthSock note above
 #   allow:
 #     - AI_GATEWAY_TOKEN     # named in a profile's tokenEnv (local/gx) — a member reaching the
 #                            # gateway is by design, not a leak

bridged/src/main/java/dev/ltms/fleet/Fleetd.java

@@ -652,8 +652,12 @@ public final class Fleetd {
     static void reportMemberCredentialsGap(FleetConfig cfg) {
         FleetConfig.MemberCredentials creds = cfg.memberCredentials();
         if (creds != null && !creds.known().isEmpty()) {
-            log.info("memberCredentials: {} known name(s), {} allowed — blocking {} on every spawn",
-                    creds.known().size(), creds.allow().size(), creds.blockedSet().size());
+            log.info("memberCredentials: policy={}, {} known name(s), {} allowed — blocking {} on "
+                            + "every spawn{}",
+                    creds.policy(), creds.known().size(), creds.allow().size(), creds.blockedSet().size(),
+                    creds.isAllowList()
+                            ? " (allow-list: known/allow are reporting only — the control is the derived ZDOTDIR scrub)"
+                            : "");
             return;
         }
         log.warn("memberCredentials: absent or empty — the daemon will start anyway, and every "

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

@@ -957,27 +957,86 @@ public record FleetConfig(
      * UNLESS it is also in {@link #allow}. A name that shows up in neither list is not silently
      * allowed — see {@code HerdrPeerLauncher}'s gap detector, which logs it.
      *
-     * @param policy how the block is computed. Only {@link #POLICY_DENY_BY_DEFAULT} is understood
-     *               today; {@code null}/blank defaults to it. An operator's own deny-list is
-     *               deliberately not supported — see above.
+     * <p><b>CB-633: allow-list.</b> Deny-by-default's overlay is applied BEFORE the pane's login
+     * shell runs, so any file that chain sources can re-export over it — and did. The allow-list
+     * policy moves the control to a generated ZDOTDIR whose startup files run the scrub LAST, after
+     * the whole operator chain, and blank every exported variable not on an allow-list DERIVED from
+     * what the launcher itself injects (profiles' tokenEnv/gitTokenEnv/gitHostEnv/env keys plus an
+     * infrastructure set) — never hand-typed, so adding a profile cannot break a spawn. Under this
+     * policy {@link #allow} and {@link #known} stop being a control and become reporting only.
+     *
+     * @param policy how the block is computed. {@link #POLICY_DENY_BY_DEFAULT} (the default; also
+     *               accepted as {@link #POLICY_DENY_LIST}) shadows each {@code known}-but-not-allowed
+     *               name in the pane-creation env overlay — which a login shell that re-exports the
+     *               name defeats (see CB-596's round-2 correction). {@link #POLICY_ALLOW_LIST}
+     *               (CB-633) replaces the overlay with a per-spawn ZDOTDIR scrub that runs AFTER the
+     *               pane's login shell has finished sourcing everything, blanking every variable not
+     *               on the DERIVED allow-list (derived from what the launcher itself injects — never
+     *               hand-typed). Under {@code allow-list}, {@link #allow} and {@link #known} are
+     *               REPORTING ONLY: they feed the gap WARN, they are no longer a control.
      * @param allow  credential names a member legitimately needs (e.g. the gateway token it reaches
-     *               the LLM through, the repo-scoped forge token it opens its own PR with). Every
-     *               name here is left unmentioned in the pane's env overlay, so the value the pane's
-     *               own (login) shell exports passes through untouched.
-     * @param known  every credential name the operator's store is known to export. Every name here
-     *               that is NOT also in {@link #allow} is overlaid with a non-secret sentinel value,
-     *               shadowing whatever the pane's login shell would otherwise export for it.
+     *               the LLM through, the repo-scoped forge token it opens its own PR with). Under
+     *               deny-list/deny-by-default every name here is left unmentioned in the pane's env
+     *               overlay; under allow-list this list is reporting only — the control is derived,
+     *               not configured.
+     * @param known  every credential name the operator's store is known to export. Under
+     *               deny-list/deny-by-default every name here that is NOT also in {@link #allow} is
+     *               overlaid with a non-secret sentinel value. Under allow-list this list is
+     *               reporting only.
+     * @param sshAuthSock whether the member may inherit {@code SSH_AUTH_SOCK} under the allow-list
+     *               policy ({@code "allow"}) or must have it blanked ({@code "block"}, the default).
+     *               This is a DECISION, never a default: {@code SSH_AUTH_SOCK} is a handle to the
+     *               operator's ssh-agent, and a member holding it can sign with the operator's own
+     *               keys — but it appears in no secret file and is credential-shaped like nothing on
+     *               any list, which is why three earlier tickets missed it (gitea #110 / CB-607).
+     *               Blocking it breaks git over SSH inside the member; allow it only when members do
+     *               not need to authenticate as the operator over SSH. Ignored under deny-list /
+     *               deny-by-default, which never touch the name.
      */
     @JsonIgnoreProperties(ignoreUnknown = true)
-    public record MemberCredentials(String policy, List<String> allow, List<String> known) {
+    public record MemberCredentials(String policy, List<String> allow, List<String> known,
+                                    String sshAuthSock) {
 
-        /** The only policy this build understands: block every {@code known} name not in {@code allow}. */
+        /** Default policy: block every {@code known} name not in {@code allow}, via the env overlay. */
         public static final String POLICY_DENY_BY_DEFAULT = "deny-by-default";
 
+        /** Alias of {@link #POLICY_DENY_BY_DEFAULT}, spelled the way CB-633 names the two policies. */
+        public static final String POLICY_DENY_LIST = "deny-list";
+
+        /**
+         * CB-633: derive the kept-name set from what the launcher itself injects, generate a
+         * per-spawn ZDOTDIR whose startup files blank every exported variable not on it AFTER the
+         * pane's shell has finished sourcing the operator's chain. The scrub is sourced from both
+         * the generated {@code .zshrc} and {@code .zlogin}, because herdr opens a LOGIN zsh on macOS
+         * and a plain interactive one on Linux — see {@code EnvAllowListScrub}.
+         */
+        public static final String POLICY_ALLOW_LIST = "allow-list";
+
+        /** The pre-CB-633 three-field form — {@code sshAuthSock} defaults to blocked. */
+        public MemberCredentials(String policy, List<String> allow, List<String> known) {
+            this(policy, allow, known, null);
+        }
+
         public MemberCredentials {
-            policy = (policy == null || policy.isBlank()) ? POLICY_DENY_BY_DEFAULT : policy.toLowerCase();
+            String normalizedPolicy = (policy == null || policy.isBlank())
+                    ? POLICY_DENY_BY_DEFAULT : policy.toLowerCase(java.util.Locale.ROOT);
+            // deny-list is an alias of deny-by-default, not a third behaviour — normalize to one
+            // spelling so every isDenyList()-style check has one value to compare against.
+            policy = POLICY_DENY_LIST.equals(normalizedPolicy) ? POLICY_DENY_BY_DEFAULT : normalizedPolicy;
             allow = allow == null ? List.of() : List.copyOf(allow);
             known = known == null ? List.of() : List.copyOf(known);
+            sshAuthSock = (sshAuthSock != null && "allow".equalsIgnoreCase(sshAuthSock.trim()))
+                    ? "allow" : "block";
+        }
+
+        /** True when this block selects the CB-633 derived-allow-list policy. */
+        public boolean isAllowList() {
+            return POLICY_ALLOW_LIST.equals(policy);
+        }
+
+        /** True when {@code SSH_AUTH_SOCK} may pass through under the allow-list policy. Default: no. */
+        public boolean sshAuthSockAllowed() {
+            return "allow".equals(sshAuthSock);
         }
 
         /** {@link #allow} as a set, for membership checks. */
@@ -1487,9 +1546,15 @@ public record FleetConfig(
         }
     }
 
-    /** The member-credential policies this build understands — {@link MemberCredentials#policy()}'s only valid value. */
+    /**
+     * The member-credential policies this build understands — {@link MemberCredentials#policy()}'s
+     * only valid values. Checked against the RAW yaml text (before {@link MemberCredentials}'s
+     * compact constructor normalizes {@code deny-list} onto {@code deny-by-default}), so the alias
+     * is listed explicitly.
+     */
     private static final Set<String> KNOWN_MEMBER_CREDENTIALS_POLICIES =
-            Set.of(MemberCredentials.POLICY_DENY_BY_DEFAULT);
+            Set.of(MemberCredentials.POLICY_DENY_BY_DEFAULT, MemberCredentials.POLICY_DENY_LIST,
+                    MemberCredentials.POLICY_ALLOW_LIST);
 
     /**
      * Reject a {@code memberCredentials.policy} that is not {@link #KNOWN_MEMBER_CREDENTIALS_POLICIES}
@@ -1602,6 +1667,9 @@ public record FleetConfig(
         // is deliberately not pre-populated with a Java-side name list (that would just reintroduce
         // the hardcoded-list defect this record replaces); the block must be configured in
         // bridged.yaml to protect anything. See fleetd.example.yaml's memberCredentials: comment.
+        // CB-633: policy stays deny-by-default here — the allow-list scrub is opt-in, because it is
+        // stricter than today's behaviour (it blanks every non-derived name, not just known ones)
+        // and an upgrade must not change what a running deployment's members inherit.
         MemberCredentials mc = memberCredentials != null ? memberCredentials
                 : new MemberCredentials(null, List.of(), List.of());
         return new FleetConfig(b, herdrSocket, profiles, g, worktreeRoot, l, timeout, pollMs,

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

@@ -0,0 +1,276 @@
+package dev.ltms.fleet.member;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Stream;
+
+/**
+ * CB-633: generates the per-spawn {@code ZDOTDIR} directory whose startup files enforce
+ * {@code memberCredentials.policy: allow-list}.
+ *
+ * <p>The seam: zsh reads its startup files from {@code $ZDOTDIR}, and the daemon puts that variable
+ * in the pane-creation env map. The operator's whole chain ({@code ~/.zshrc} → secret store) runs
+ * inside those files, so a scrub appended to the LAST one runs after everything the operator
+ * sourced, and nothing later can re-export over it. This is the property CB-596's env-overlay
+ * control lacked: herdr applies that overlay BEFORE the shell starts, so any sourced file can undo
+ * it — and did.
+ *
+ * <p><b>Which file is last depends on the platform, so the scrub runs from two of them.</b> zsh
+ * reads {@code .zshenv} always, {@code .zprofile} and {@code .zlogin} only for a LOGIN shell, and
+ * {@code .zshrc} only for an INTERACTIVE one. herdr does not open the same kind of shell
+ * everywhere — measured on herdr 0.8.0: macOS panes run {@code -zsh} (login, so {@code .zlogin}
+ * runs), Linux panes run a plain {@code /usr/bin/zsh} (interactive but NOT login, so
+ * {@code .zlogin} never runs at all). A scrub in {@code .zlogin} alone is therefore a control that
+ * silently does nothing on Linux — the exact failure this class exists to remove, one platform
+ * over.
+ *
+ * <p>So both {@code .zshrc} and {@code .zlogin} source the same generated {@code scrub.zsh} after
+ * sourcing their {@code $HOME} counterpart. On Linux only the first fires; on macOS both do, and
+ * the second pass is deliberate rather than merely harmless — it re-scrubs anything the operator's
+ * own {@code ~/.zlogin} exported after {@code .zshrc} had finished. Re-running is idempotent: a
+ * name already blank is blanked again, and the report is rewritten with the same counts.
+ *
+ * <p>Each generated file sources its {@code $HOME} counterpart FIRST, so {@code PATH} and every
+ * toolchain binary still resolve exactly as the operator configured them; only afterwards does
+ * {@code .zlogin} run the scrub: every EXPORTED variable not on the derived allow-list is re-exported
+ * blank. Blank, not credential-shaped-pattern-filtered: a pattern list ({@code *TOKEN*}, …) is an
+ * enumeration and misses what it did not think of — a username is the other half of a credential and
+ * is shaped like none. Credential-SHAPED names among the blanked set go to the WARN log only,
+ * never to the control.
+ *
+ * <p>The scrub also writes {@code scrub-report.txt} into its own directory: one {@code allowed N of
+ * M} line (N = exports left untouched, M = exports present when the scrub ran), then the blanked
+ * NAMES — never values. The launcher reads this back at teardown and logs it, because a blocked
+ * count next to an unknown denominator is not a finding.
+ */
+public final class EnvAllowListScrub {
+
+    private static final Logger log = LoggerFactory.getLogger(EnvAllowListScrub.class);
+
+    /** Name of the report file written into the generated directory by the scrub itself. */
+    static final String REPORT_FILE = "scrub-report.txt";
+
+    /** The scrub body, generated once and sourced from both {@code .zshrc} and {@code .zlogin}. */
+    static final String SCRUB_FILE = "scrub.zsh";
+
+    /** Prefix of every generated directory — also what {@link #reapOrphans} matches on. */
+    static final String DIR_PREFIX = "bridged-zdotdir-";
+
+    /**
+     * How old an orphan must be before {@link #reapOrphans} removes it. Comfortably longer than any
+     * spawn takes, so a directory belonging to a pane that is still starting is never removed.
+     */
+    private static final Duration ORPHAN_AGE = Duration.ofHours(24);
+
+    /** Appended to the two startup files that must run the scrub, after their {@code $HOME} source. */
+    private static final String SOURCE_SCRUB =
+            "source \"$ZDOTDIR/" + SCRUB_FILE + "\"\n";
+
+    private EnvAllowListScrub() {
+    }
+
+    /**
+     * A parsed {@code scrub-report.txt}: how many exported variables existed when the scrub ran,
+     * how many were left untouched (allowed), and the NAMES that were blanked. Values never appear.
+     */
+    record ScrubReport(int allowed, int total, List<String> blanked) {
+    }
+
+    /**
+     * Create a fresh ZDOTDIR directory under {@code parentDir} holding the four zsh startup files.
+     * Every file (and the directory) registers {@code deleteOnExit}, next to the existing per-spawn
+     * charter/config temp cleanup; the launcher additionally deletes eagerly at pane release.
+     *
+     * @param allowedNames the DERIVED allow-list — exact variable names that must survive the scrub
+     * @return the directory path (to be passed as the pane's {@code ZDOTDIR})
+     * @throws UncheckedIOException when the directory or any file cannot be written — a spawn whose
+     *                              protection cannot even be materialized must fail loudly rather
+     *                              than start unprotected
+     */
+    public static Path generate(Path parentDir, Set<String> allowedNames) {
+        try {
+            reapOrphans(parentDir);
+            Path dir = Files.createTempDirectory(parentDir, DIR_PREFIX);
+            dir.toFile().deleteOnExit();
+            // The report is written by zsh, after these hooks are registered, so register its path
+            // too — otherwise the directory is non-empty at JVM exit and cannot be removed at all.
+            dir.resolve(REPORT_FILE).toFile().deleteOnExit();
+            write(dir, SCRUB_FILE, scrubScript(allowedNames));
+            write(dir, ".zshenv", homeSourcingFile(".zshenv"));
+            write(dir, ".zprofile", homeSourcingFile(".zprofile"));
+            write(dir, ".zshrc", homeSourcingFile(".zshrc") + SOURCE_SCRUB);
+            write(dir, ".zlogin", homeSourcingFile(".zlogin") + SOURCE_SCRUB);
+            return dir;
+        } catch (IOException e) {
+            throw new UncheckedIOException("cannot generate ZDOTDIR scrub files under " + parentDir, e);
+        }
+    }
+
+    /** One operator-sourcing startup file: source the {@code $HOME} counterpart, change nothing else. */
+    private static String homeSourcingFile(String name) {
+        return """
+                # generated by fleetd (CB-633 memberCredentials policy=allow-list) — do not edit.
+                # Source the operator's own %s first, so PATH and the agent binaries resolve as usual.
+                [ -r "$HOME/%s" ] && source "$HOME/%s"
+                """.formatted(name, name, name);
+    }
+
+    /**
+     * The generated {@code scrub.zsh} — the scrub body on its own, so the two startup files that
+     * must run it ({@code .zshrc} and {@code .zlogin}) hold one copy between them rather than two
+     * that can drift. Package-private so tests can assert on the exact script handed to zsh — the
+     * artefact here IS a shell file, and a test that checks only the Java string assembly proves
+     * nothing about whether zsh accepts it.
+     */
+    static String scrubScript(Set<String> allowedNames) {
+        StringBuilder names = new StringBuilder();
+        for (String n : allowedNames.stream().sorted().toList()) {
+            if (names.length() > 0) {
+                names.append(' ');
+            }
+            // Names are validated against [A-Za-z_][A-Za-z0-9_]* before they get here; single quotes
+            // keep even a non-conforming name inert rather than executable.
+            names.append('\'').append(n.replace("'", "")).append('\'');
+        }
+        return """
+                # generated by fleetd (CB-633 memberCredentials policy=allow-list) — do not edit.
+                # Sourced from .zshrc and again from .zlogin, each time AFTER that file has sourced
+                # its $HOME counterpart — so this runs after everything the operator sourced, on a
+                # login shell (macOS panes) and on a plain interactive one (Linux panes) alike.
+                # Running twice is idempotent and deliberate: the second pass catches anything
+                # ~/.zlogin exported after ~/.zshrc had finished.
+
+                typeset -A _cb633_allowed
+                for _cb633_n in %s; do _cb633_allowed[$_cb633_n]=1; done
+
+                # Enumerate EXPORTED variable NAMES from `env` itself. Deliberately NOT the special
+                # `parameters` assoc: its subscript is evaluated arithmetically on this host's zsh
+                # and blows up on some names ("bad math expression"). Names not matching the
+                # identifier pattern (junk from multi-line values) are skipped, never scrubbed.
+                typeset -a _cb633_names
+                _cb633_names=("${(@f)$(command env | command cut -d= -f1)}")
+                typeset -a _cb633_blank
+                _cb633_blank=()
+                integer _cb633_total=0
+                for _cb633_n in "${_cb633_names[@]}"; do
+                  [[ "$_cb633_n" =~ ^[A-Za-z_][A-Za-z0-9_]*$ ]] || continue
+                  (( _cb633_total += 1 ))
+                  [[ -n "${_cb633_allowed[$_cb633_n]-}" ]] && continue
+                  case "$_cb633_n" in %s) continue ;; esac
+                  _cb633_blank+=("$_cb633_n")
+                done
+
+                { for _cb633_n in "${_cb633_blank[@]}"; do export "$_cb633_n="; done; } 2>/dev/null
+
+                integer _cb633_kept=$(( _cb633_total - ${#_cb633_blank} ))
+                {
+                  print -r -- "allowed $_cb633_kept of $_cb633_total"
+                  for _cb633_n in "${_cb633_blank[@]}"; do print -r -- "$_cb633_n"; done
+                } > "$ZDOTDIR/%s" 2>/dev/null
+
+                unset _cb633_allowed _cb633_names _cb633_blank _cb633_n _cb633_total _cb633_kept
+                """.formatted(names, MemberEnvAllowList.zshCasePattern(), REPORT_FILE);
+    }
+
+    private static void write(Path dir, String fileName, String content) throws IOException {
+        Path file = dir.resolve(fileName);
+        Files.writeString(file, content);
+        file.toFile().deleteOnExit();
+    }
+
+    /**
+     * Read and parse {@link #REPORT_FILE} out of a generated ZDOTDIR directory. Returns {@code null}
+     * when absent or unreadable (the pane may have been torn down before its login shell ever got to
+     * the scrub) — callers treat that as "no measurement available", never as success.
+     */
+    static ScrubReport readReport(Path zdotdir) {
+        Path report = zdotdir.resolve(REPORT_FILE);
+        if (!Files.isRegularFile(report)) {
+            return null;
+        }
+        try {
+            List<String> lines = Files.readAllLines(report);
+            if (lines.isEmpty() || !lines.getFirst().startsWith("allowed ")) {
+                return null;
+            }
+            String[] parts = lines.getFirst().substring("allowed ".length()).trim().split("\\s+");
+            if (parts.length != 3 || !"of".equals(parts[1])) {
+                return null;
+            }
+            List<String> blanked = new ArrayList<>();
+            for (int i = 1; i < lines.size(); i++) {
+                if (!lines.get(i).isBlank()) {
+                    blanked.add(lines.get(i));
+                }
+            }
+            return new ScrubReport(Integer.parseInt(parts[0]), Integer.parseInt(parts[2]),
+                    List.copyOf(blanked));
+        } catch (IOException | NumberFormatException e) {
+            return null;
+        }
+    }
+
+    /** Best-effort recursive delete; failures are swallowed — JVM-exit cleanup is the backstop. */
+    /**
+     * Remove generated directories left behind by an earlier daemon process.
+     *
+     * <p>{@link #generate} registers each directory for deletion at JVM exit, which covers a clean
+     * shutdown and covers nothing else. A {@code kill -9}, a crash, or a host reboot leaves the
+     * directory in the temp dir for good, and the daemon is restarted often enough that these
+     * accumulate. They hold no secrets — the generated files contain variable NAMES and a report of
+     * names, never a value — but an unbounded pile of them in {@code /tmp} is still our mess to
+     * clear.
+     *
+     * <p>Called from {@link #generate}, so it runs on the path that creates them and needs no
+     * separate wiring or scheduler. Only directories older than {@link #ORPHAN_AGE} are touched,
+     * which keeps it clear of any pane that is merely still starting, including one belonging to a
+     * different daemon instance running right now. Best-effort: every failure is ignored, because
+     * tidying temp files must never be the reason a spawn fails.
+     */
+    static void reapOrphans(Path parentDir) {
+        Instant cutoff = Instant.now().minus(ORPHAN_AGE);
+        try (Stream<Path> entries = Files.list(parentDir)) {
+            entries.filter(d -> d.getFileName().toString().startsWith(DIR_PREFIX))
+                    .filter(Files::isDirectory)
+                    .filter(d -> olderThan(d, cutoff))
+                    .forEach(EnvAllowListScrub::deleteRecursively);
+        } catch (IOException | RuntimeException e) {
+            log.debug("could not scan {} for orphaned ZDOTDIRs: {}", parentDir, e.toString());
+        }
+    }
+
+    private static boolean olderThan(Path dir, Instant cutoff) {
+        try {
+            return Files.getLastModifiedTime(dir).toInstant().isBefore(cutoff);
+        } catch (IOException e) {
+            return false; // unreadable timestamp ⇒ leave it alone
+        }
+    }
+
+    static void deleteRecursively(Path dir) {
+        if (dir == null || !Files.exists(dir)) {
+            return;
+        }
+        try (Stream<Path> walk = Files.walk(dir)) {
+            walk.sorted(java.util.Comparator.reverseOrder()).forEach(p -> {
+                try {
+                    Files.deleteIfExists(p);
+                } catch (IOException ignored) {
+                    // best effort — deleteOnExit retries at JVM shutdown
+                }
+            });
+        } catch (IOException ignored) {
+            // same
+        }
+    }
+}

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

@@ -156,6 +156,20 @@ public abstract class HerdrPeerLauncher implements PeerLauncher {
     private final ConcurrentMap<String, String> paneByAgentId = new ConcurrentHashMap<>();
     private final AtomicBoolean resetUnsupportedLogged = new AtomicBoolean();
 
+    /**
+     * CB-633: the per-spawn ZDOTDIR directory generated for a pane under
+     * {@code memberCredentials.policy: allow-list}, keyed by herdr pane id so every teardown exit
+     * ({@link #stop} is reached from explicit DELETE, orphan reap, and the spawn-readiness gate
+     * timeout alike) can read the scrub's own report and then remove the directory. A pane that
+     * never reaches {@code stop} (spawn failure) leaks its directory only until JVM exit, where the
+     * generator's {@code deleteOnExit} hooks are the backstop — the same cleanup shape the existing
+     * charter/config temp files use.
+     */
+    private final ConcurrentMap<String, Path> zdotdirByPane = new ConcurrentHashMap<>();
+
+    /** Guards {@link #warnNonZsh} to one WARN per launcher instance, not one per spawn. */
+    private final AtomicBoolean nonZshShellWarned = new AtomicBoolean();
+
     /**
      * @param namePrefix          label prefix for this peer kind (drives naming and reap)
      * @param agents              herdr agent control (start, status, close)
@@ -420,9 +434,27 @@ public abstract class HerdrPeerLauncher implements PeerLauncher {
         try {
             Launch launch = buildLaunch(cfg, new LaunchSpec(sessionName, resumeSessionId, role, charter,
                     roleCharter, replyCharter, cwd));
-            Agent agent = cfg.tabPlacement()
-                    ? spawnInTab(cfg, launch.env(), launch.argv(), cwd, role, liveFleet)
-                    : spawnAsPane(cfg, launch.env(), launch.argv(), cwd, charter);
+            // CB-633: applied AFTER buildLaunch so the generated scrub's allow-list can also cover
+            // the exact env-map keys this launch injects (ANTHROPIC_*, OPENCODE_CONFIG, GITEA_TOKEN, …)
+            // — anything the daemon deliberately sets must survive its own control.
+            Path zdotdir = applyEnvironmentAllowListPolicy(cfg, launch);
+            Agent agent;
+            try {
+                agent = cfg.tabPlacement()
+                        ? spawnInTab(cfg, launch.env(), launch.argv(), cwd, role, liveFleet)
+                        : spawnAsPane(cfg, launch.env(), launch.argv(), cwd, charter);
+            } catch (RuntimeException e) {
+                // A failed spawn has no pane id, so nothing would ever key this directory for
+                // teardown and it would sit in the temp dir until the JVM exits cleanly — which,
+                // for a daemon, may be never. Remove it on the way out.
+                if (zdotdir != null) {
+                    EnvAllowListScrub.deleteRecursively(zdotdir);
+                }
+                throw e;
+            }
+            if (zdotdir != null) {
+                zdotdirByPane.put(agent.paneId(), zdotdir);
+            }
             logCharterReceipt(receipt, true);
             return new Spawned(agent, launch.agentSessionId(), receipt);
         } catch (RuntimeException e) {
@@ -774,6 +806,14 @@ public abstract class HerdrPeerLauncher implements PeerLauncher {
             log.debug("not closing tab {} — it holds {} panes (not a dedicated peer tab)",
                     loc.tabId(), loc.tabPaneCount());
         }
+        // CB-633: log this pane's allowed-N-of-M scrub report, then remove the generated ZDOTDIR.
+        // Last in, best-effort — a failure here must not mask a real teardown failure above.
+        try {
+            releaseZdotdir(paneId);
+        } catch (RuntimeException e) {
+            log.warn("memberCredentials allow-list: releasing ZDOTDIR for pane {} failed: {}",
+                    paneId, e.getMessage());
+        }
     }
 
     /** Whether any configured profile places peers in their own tab (so tabs may need cleanup). */
@@ -957,16 +997,134 @@ public abstract class HerdrPeerLauncher implements PeerLauncher {
      * one whose {@code known} list is empty — shadows nothing. This is a real, config-driven gap
      * (see {@link FleetConfig.MemberCredentials}'s javadoc), not a safe default: deny-by-default
      * only defends names the operator has actually enumerated in {@code known}.
+     *
+     * <p>CB-633: under {@code policy: allow-list} this overlay is NOT the control anymore — it is
+     * applied before the login shell runs and a sourced file can (and did) undo it. The control is
+     * the ZDOTDIR scrub ({@link #applyEnvironmentAllowListPolicy}); {@code known}/{@code allow}
+     * remain as reporting only via {@link #logCredentialGap}.
      */
     private void applyMemberCredentialPolicy(Map<String, String> workerEnv) {
         FleetConfig.MemberCredentials creds = memberCredentials == null ? null : memberCredentials.get();
         if (creds == null) {
             return;
         }
+        if (!creds.isAllowList()) {
+            overlayBlockedCredentials(workerEnv, creds);
+        }
+        logCredentialGap(creds);
+    }
+
+    /** Put {@link #BLOCKED_CREDENTIAL_SENTINEL} over every blocked name in the pane-creation env map. */
+    private static void overlayBlockedCredentials(Map<String, String> workerEnv,
+                                                  FleetConfig.MemberCredentials creds) {
         for (String name : creds.blockedSet()) {
             workerEnv.put(name, BLOCKED_CREDENTIAL_SENTINEL);
         }
-        logCredentialGap(creds);
+    }
+
+    /**
+     * CB-633: under {@code memberCredentials.policy: allow-list}, generate the per-spawn ZDOTDIR
+     * directory whose startup files blank every exported variable not on the DERIVED allow-list —
+     * running AFTER the pane's shell has finished sourcing the operator's chain, which is what no
+     * pre-shell env overlay can achieve. {@code EnvAllowListScrub} sources the scrub from both the
+     * generated {@code .zshrc} and {@code .zlogin}, since a herdr pane is a login shell on macOS
+     * and a plain interactive one on Linux. Mutates {@code launch.env()} to carry
+     * {@code ZDOTDIR=<dir>}, so both placement paths ({@link #spawnInTab}, {@link #spawnAsPane})
+     * pass it through {@code tab.create}/{@code pane.split}. Returns the directory for teardown
+     * registration, or {@code null} when the policy does not apply.
+     *
+     * <p>The allow-list handed to the generator is the derived profile set ({@link
+     * MemberEnvAllowList#derive}) UNIONed with the exact keys of THIS launch's env map — names the
+     * daemon itself injects must survive its own control. {@code SSH_AUTH_SOCK} is added ONLY when
+     * the config explicitly allows it; by default it is absent, so the scrub blanks it like any
+     * other non-derived name.
+     */
+    private Path applyEnvironmentAllowListPolicy(FleetConfig.Profile cfg, Launch launch) {
+        FleetConfig.MemberCredentials creds = memberCredentials == null ? null : memberCredentials.get();
+        if (creds == null || !creds.isAllowList()) {
+            return null;
+        }
+        String loginShell = resolveEnv("SHELL");
+        boolean zsh = loginShell != null && (loginShell.endsWith("/zsh") || loginShell.equals("zsh"));
+        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
+            // sentinel overlay over the enumerated known: names — weaker (a sourced file can undo
+            // it), but strictly better than nothing.
+            warnNonZsh(loginShell);
+            overlayBlockedCredentials(launch.env(), creds);
+            logCredentialGap(creds);
+            return null;
+        }
+        Set<String> allowed = new java.util.TreeSet<>(MemberEnvAllowList.derive(profiles.values()));
+        if (creds.sshAuthSockAllowed()) {
+            allowed.add(SSH_AUTH_SOCK);
+        } // blocked by default: absent from the set ⇒ blanked by the scrub like any other name
+        allowed.addAll(launch.env().keySet());
+        Path dir = EnvAllowListScrub.generate(Path.of(System.getProperty("java.io.tmpdir")), 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",
+                cfg.profile(), dir.getFileName(), allowed.size());
+        return dir;
+    }
+
+    /** The operator ssh-agent handle — kept ONLY by explicit config decision, never by default. */
+    private static final String SSH_AUTH_SOCK = "SSH_AUTH_SOCK";
+
+    /**
+     * CB-633: a non-zsh login shell means the allow-list control CANNOT run — say so once per
+     * launcher instance, naming the shell, instead of failing silently.
+     */
+    private void warnNonZsh(String shell) {
+        if (nonZshShellWarned.compareAndSet(false, true)) {
+            log.warn("memberCredentials policy=allow-list: member login shell '{}' is NOT zsh — "
+                            + "ZDOTDIR scrubbing cannot run, so members' inherited environment is "
+                            + "UNPROTECTED beyond the enumerated known: fallback. Move herdr onto a "
+                            + "zsh account or switch policy back to deny-by-default.",
+                    shell == null ? "<unset>" : shell);
+        }
+    }
+
+    /**
+     * 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
+     * every teardown exit already goes through.
+     *
+     * <p><b>A missing report is a WARN, not a debug line.</b> The report is the only evidence that
+     * the scrub ran at all in that pane. Its absence has an innocent reading — the pane died before
+     * its shell finished starting — and a serious one: the shell was not zsh, or it read its
+     * startup files from somewhere other than the directory we generated, in which case the member
+     * ran for its whole life with the operator's full secret store in its environment and nothing
+     * said so. We cannot tell those two apart from here, so the line says what is and is not known
+     * rather than picking one. Logging this at debug is how a control that silently stopped working
+     * stays unnoticed — the failure mode this whole class exists to remove.
+     */
+    private void releaseZdotdir(String paneId) {
+        Path dir = zdotdirByPane.remove(paneId);
+        if (dir == null) {
+            return;
+        }
+        EnvAllowListScrub.ScrubReport report = EnvAllowListScrub.readReport(dir);
+        if (report == null) {
+            log.warn("memberCredentials allow-list: pane {} left no scrub report in {} — the "
+                    + "environment scrub cannot be confirmed to have run. Either the pane ended "
+                    + "before its shell finished starting, or its shell never read our generated "
+                    + "startup files, in which case that member saw the full host environment.",
+                    paneId, dir);
+        } else {
+            log.info("memberCredentials allow-list: pane {} allowed {} of {} environment variables",
+                    paneId, report.allowed(), report.total());
+            List<String> shaped = report.blanked().stream()
+                    .filter(name -> CREDENTIAL_SHAPED_NAME.matcher(name).matches())
+                    .toList();
+            if (!shaped.isEmpty()) {
+                log.warn("memberCredentials allow-list: pane {} blanked credential-shaped variable(s) "
+                        + "{} — confirm none of them was something a member legitimately needed",
+                        paneId, shaped);
+            }
+        }
+        EnvAllowListScrub.deleteRecursively(dir);
     }
 
     /** Credential-shaped env var name heuristic for {@link #logCredentialGap} — case-insensitive. */

bridged/src/main/java/dev/ltms/fleet/member/MemberEnvAllowList.java

@@ -0,0 +1,112 @@
+package dev.ltms.fleet.member;
+
+import dev.ltms.fleet.config.FleetConfig;
+
+import java.util.Collection;
+import java.util.Set;
+import java.util.TreeSet;
+
+/**
+ * CB-633: the set of environment variable NAMES a spawned member is allowed to keep under
+ * {@code memberCredentials.policy: allow-list} — DERIVED from what the launcher itself injects,
+ * never hand-typed.
+ *
+ * <p>A hand-typed allow-list is the defect this class exists to prevent: a name an operator forgets
+ * to type is a credential that passes through to every member, and a profile added to config later
+ * would silently break spawns whose scrub did not know its names. Derivation closes both ends. The
+ * kept-name set is the union of:
+ *
+ * <ul>
+ *   <li>every configured {@link FleetConfig.Profile profile}'s {@code gitTokenEnv},
+ *       {@code gitHostEnv}, and {@code tokenEnv} values — these are variable <em>names</em> held in
+ *       config, and the launcher reads their values out of exactly these variables;</li>
+ *   <li>every key of every profile's {@code env:} map — anything the operator routes into a pane on
+ *       purpose;</li>
+ *   <li>{@link #INFRASTRUCTURE_PASSTHROUGH} — names that are not credentials at all but that a shell
+ *       or the agent binary genuinely needs to function.</li>
+ * </ul>
+ *
+ * <p>Because the union spans EVERY profile (not just the one spawning), adding a new profile can
+ * only ever widen the list — it cannot break another spawn's scrub. And because the launcher also
+ * unions in the exact keys of each spawn's own env map at generation time (see {@code
+ * HerdrPeerLauncher}), anything the daemon deliberately injects for THIS spawn survives its own
+ * control.
+ *
+ * <p>{@code SSH_AUTH_SOCK} is deliberately NOT here. It is a handle to the operator's ssh-agent — a
+ * member holding it can sign with the operator's keys — so keeping it is a config decision
+ * ({@code memberCredentials.sshAuthSock: allow}), not a derivation default.
+ */
+public final class MemberEnvAllowList {
+
+    /**
+     * Names that are not credentials and that a login shell or agent binary genuinely needs.
+     *
+     * <p>Every name here is a location or a shell setting, never a credential. That rule is load
+     * bearing, and CB-633's first cut broke it: it also listed {@code ANTHROPIC_AUTH_TOKEN},
+     * {@code GITEA_TOKEN}, {@code GITEA_HOST}, {@code ANTHROPIC_BASE_URL}, {@code ANTHROPIC_MODEL},
+     * {@code CLAUDE_CONFIG_DIR}, {@code OPENCODE_CONFIG} and {@code BRIDGED_MEMBER} "because the
+     * launcher injects them". The launcher does — but only on the spawns where it actually sets
+     * them, and {@code HerdrPeerLauncher} already unions THIS spawn's env-map keys into the
+     * allow-list. So a static entry adds nothing on a spawn that injects the name, and on a spawn
+     * that does not it lets the operator's own value through under exactly the name a member reads.
+     * {@code ANTHROPIC_BASE_URL} is the sharpest case: an inherited one silently moves a member off
+     * the endpoint the profile chose.
+     *
+     * <p>{@code ZDOTDIR} stays because it is this control's own handle — lose it and every later
+     * sub-shell loses the scrub. {@code JAVA_HOME} and the {@code XDG_*} roots are toolchain
+     * locations. Everything else a member needs must arrive via a profile's {@code env:} or the
+     * launcher's own injection, both of which land on the derived set automatically.
+     */
+    public static final Set<String> INFRASTRUCTURE_PASSTHROUGH = Set.of(
+            "PATH", "HOME", "SHELL", "TERM", "LANG", "TMPDIR",
+            "USER", "LOGNAME", "PWD", "SHLVL", "EDITOR", "PAGER",
+            "_",
+            "ZDOTDIR",
+            "JAVA_HOME",
+            "XDG_CONFIG_HOME", "XDG_DATA_HOME", "XDG_CACHE_HOME", "XDG_STATE_HOME");
+
+    /** Locale-category prefix kept as infrastructure ({@code LC_ALL}, {@code LC_CTYPE}, …). */
+    private static final String INFRASTRUCTURE_NAME_PREFIX = "LC_";
+
+    private MemberEnvAllowList() {
+    }
+
+    /**
+     * Derive the allowed NAME set from the given profiles plus {@link #INFRASTRUCTURE_PASSTHROUGH}.
+     * Deterministic (sorted) so generated scrub files are diffable run-to-run.
+     */
+    public static Set<String> derive(Collection<FleetConfig.Profile> profiles) {
+        Set<String> derived = new TreeSet<>(INFRASTRUCTURE_PASSTHROUGH);
+        if (profiles != null) {
+            for (FleetConfig.Profile p : profiles) {
+                addIfPresent(derived, p.gitTokenEnv());
+                addIfPresent(derived, p.gitHostEnv());
+                addIfPresent(derived, p.tokenEnv());
+                if (p.env() != null) {
+                    derived.addAll(p.env().keySet());
+                }
+            }
+        }
+        return Set.copyOf(derived);
+    }
+
+    /**
+     * Whether {@code name} survives the scrub when {@code allowedNames} is the derived set: an exact
+     * match, or an infrastructure-prefixed name ({@code LC_*}). Prefix rules live ONLY here and in
+     * the generated script's {@code case} pattern, which is written from this constant's value.
+     */
+    public static boolean keeps(Set<String> allowedNames, String name) {
+        return allowedNames.contains(name) || name.startsWith(INFRASTRUCTURE_NAME_PREFIX);
+    }
+
+    /** The prefix rule as a zsh {@code case} pattern, so the script and Java cannot drift apart. */
+    public static String zshCasePattern() {
+        return INFRASTRUCTURE_NAME_PREFIX + "*";
+    }
+
+    private static void addIfPresent(Set<String> into, String name) {
+        if (name != null && !name.isBlank()) {
+            into.add(name);
+        }
+    }
+}

bridged/src/test/java/dev/ltms/fleet/config/FleetConfigTest.java

@@ -1513,6 +1513,66 @@ class FleetConfigTest {
                 "blockedSet is known minus allow");
     }
 
+    /**
+     * CB-633: {@code policy: allow-list} binds, is case-insensitive, and flips the block into
+     * derived-scrub mode ({@link FleetConfig.MemberCredentials#isAllowList()}).
+     */
+    @Test
+    void allowListPolicyBinds(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("member-credentials-allow-list.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                memberCredentials:
+                  policy: ALLOW-LIST
+                """);
+
+        FleetConfig.MemberCredentials mc = FleetConfig.load(f).memberCredentials();
+        assertEquals(FleetConfig.MemberCredentials.POLICY_ALLOW_LIST, mc.policy());
+        assertTrue(mc.isAllowList(), "allow-list must select the CB-633 derived-scrub policy");
+    }
+
+    /**
+     * CB-633: {@code deny-list} is an accepted spelling of today's behaviour, normalized onto the
+     * one canonical value — an operator upgrading from prose that says "deny-list" must not be told
+     * their policy is unrecognized.
+     */
+    @Test
+    void denyListIsAnAcceptedAliasOfDenyByDefault(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("member-credentials-deny-list.yaml");
+        Files.writeString(f, """
+                bind:
+                  port: 8080
+                memberCredentials:
+                  policy: deny-list
+                  known:
+                    - GITEA_ACCESS_TOKEN
+                """);
+
+        FleetConfig.MemberCredentials mc = FleetConfig.load(f).memberCredentials();
+        assertFalse(mc.isAllowList());
+        assertEquals(FleetConfig.MemberCredentials.POLICY_DENY_BY_DEFAULT, mc.policy(),
+                "deny-list normalizes onto the canonical deny-by-default value");
+    }
+
+    /**
+     * CB-633: {@code SSH_AUTH_SOCK} is a decision, never a default — absent, blank, or misspelled,
+     * it stays BLOCKED; only the literal "allow" (any case) passes it through. A typo like "alow"
+     * failing safe here is the whole point of making it a knob.
+     */
+    @Test
+    void sshAuthSockDefaultsToBlockedAndOnlyExplicitAllowUnblocksIt() {
+        assertTrue(new FleetConfig.MemberCredentials("allow-list", List.of(), List.of()).sshAuthSock().equals("block"),
+                "absent knob blocks SSH_AUTH_SOCK");
+        assertFalse(new FleetConfig.MemberCredentials("allow-list", List.of(), List.of()).sshAuthSockAllowed());
+        assertFalse(new FleetConfig.MemberCredentials(null, null, null, "").sshAuthSockAllowed(),
+                "blank knob blocks SSH_AUTH_SOCK");
+        assertFalse(new FleetConfig.MemberCredentials(null, null, null, "alow").sshAuthSockAllowed(),
+                "a misspelled value fails SAFE, not open");
+        assertTrue(new FleetConfig.MemberCredentials(null, null, null, "ALLOW").sshAuthSockAllowed(),
+                "the literal allow (case-insensitive) unblocks SSH_AUTH_SOCK");
+    }
+
     /**
      * CB-596: omitting {@code memberCredentials:} entirely must NOT crash a reader that assumes a
      * non-null block (the same "fill in nested defaults" contract every other structural field

bridged/src/test/java/dev/ltms/fleet/member/EnvAllowListScrubTest.java

@@ -0,0 +1,211 @@
+package dev.ltms.fleet.member;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.TreeSet;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assumptions.assumeTrue;
+
+/**
+ * CB-633: the artefact here is a shell file handed to ANOTHER PROGRAM — so the only test that
+ * proves anything is one that runs that program. A unit test on {@link EnvAllowListScrub}'s string
+ * assembly proves nothing about zsh; this repo has shipped a green suite before whose tests checked
+ * argv we build and none ran the binary that has to accept it.
+ *
+ * <p>This test starts a REAL login interactive zsh from a CLEAN parent ({@code env -i}), once with
+ * the generated ZDOTDIR and once without (the baseline), and asserts the surviving exported NAME set
+ * EQUALS the allow-list intersection of the baseline — equality, not "these names are blocked". A
+ * blocked-name list can only check names somebody already thought of; that is exactly the failure
+ * being fixed. Only NAMES are compared — never values.
+ *
+ * <p>The scrub run sources this operator's real {@code ~/.zshenv}/~/.zprofile/~/.zshrc/~/.zlogin}
+ * chain, so it skips cleanly (JUnit {@code assumeTrue}) on a machine with no /bin/zsh or no real
+ * shell rc files rather than failing there.
+ */
+class EnvAllowListScrubTest {
+
+    private static final Path ZSH = Path.of("/bin/zsh");
+
+    /** Env var names appearing in command output; anything else (prompts, wrapped lines) is noise. */
+    private static final Pattern ENV_NAME = Pattern.compile("^([A-Za-z_][A-Za-z0-9_]*)$");
+
+    /**
+     * The equality test. Expected survivors = baseline exports ∩ allowed — i.e. every survivor is
+     * allowed AND every allowed name that existed survives. The operator's own secret-store exports
+     * (~30 names on this host) are the decoys: none is on the derived list, so every one must be
+     * gone from the scrub run.
+     */
+    @Test
+    void scrubbedLoginShellSurvivorsEqualTheDerivedAllowList(@TempDir Path tmp) throws Exception {
+        assumeTrue(Files.isExecutable(ZSH), "/bin/zsh not present — nothing to prove here");
+        Path homeZshrc = Path.of(System.getProperty("user.home"), ".zshrc");
+        assumeTrue(Files.exists(homeZshrc), "$HOME/.zshrc does not exist — no real login chain to test against");
+
+        // Derived shape, zero profiles: infrastructure + LC_* rule. SSH_AUTH_SOCK deliberately NOT
+        // included — blocked by default is the decision under test.
+        Set<String> allowed = MemberEnvAllowList.derive(List.of());
+        Path zdotdir = EnvAllowListScrub.generate(tmp, allowed);
+
+        Map<String, String> cleanParent = Map.of(
+                "HOME", System.getProperty("user.home"),
+                "PATH", "/usr/bin:/bin",
+                "SHELL", "/bin/zsh",
+                "USER", System.getProperty("user.name", "nobody"),
+                "TMPDIR", tmp.toString());
+
+        Set<String> baseline = exportedNamesFromCleanParent(cleanParent, null);
+        Set<String> scrubbed = exportedNamesFromCleanParent(cleanParent, zdotdir);
+
+        // The scrub RUN itself carries ZDOTDIR (the harness set it; it is infrastructure and MUST
+        // survive, or every later login shell loses the scrub) — so the expected set starts from
+        // baseline plus that one name.
+        Set<String> expected = new TreeSet<>();
+        for (String name : baseline) {
+            if (MemberEnvAllowList.keeps(allowed, name)) {
+                expected.add(name);
+            }
+        }
+        assertTrue(MemberEnvAllowList.keeps(allowed, "ZDOTDIR"));
+        expected.add("ZDOTDIR");
+        assertEquals(expected, scrubbed,
+                "surviving exported names must EQUAL baseline ∩ allow-list — a survivor outside the "
+                        + "list is a leak; a missing allowed name means the scrub broke something it "
+                        + "should have kept. Names only, values never printed.");
+    }
+
+    /** The scrub writes its denominator report next to itself; names only, parseable. */
+    @Test
+    void scrubWritesAnAllowedNofMReport(@TempDir Path tmp) throws Exception {
+        Set<String> allowed = MemberEnvAllowList.derive(List.of());
+        Path zdotdir = EnvAllowListScrub.generate(tmp, allowed);
+
+        Map<String, String> cleanParent = Map.of(
+                "HOME", System.getProperty("user.home"),
+                "PATH", "/usr/bin:/bin",
+                "SHELL", "/bin/zsh");
+        exportedNamesFromCleanParent(cleanParent, zdotdir); // runs the login shell → runs the scrub
+
+        EnvAllowListScrub.ScrubReport report = EnvAllowListScrub.readReport(zdotdir);
+        assertNotNull(report, "a completed login shell must leave a report behind");
+        assertTrue(report.allowed() >= 0 && report.total() >= report.allowed(),
+                "allowed N of M with N <= M — the denominator is always reported");
+    }
+
+    /** Report parsing is lenient: absent file → null (no measurement), not an exception. */
+    @Test
+    void readReportReturnsNullForADirectoryWithoutOne(@TempDir Path dir) {
+        assertNull(EnvAllowListScrub.readReport(dir));
+    }
+
+    /**
+     * The same equality, for a shell that is INTERACTIVE but NOT a login shell — the shape herdr
+     * opens on Linux.
+     *
+     * <p>Why this test exists. The first version of this control put the scrub in {@code .zlogin}
+     * alone. zsh reads {@code .zlogin} only for a login shell, and herdr does not open one
+     * everywhere: measured on herdr 0.8.0, a macOS pane runs {@code -zsh} (login) while a Linux pane
+     * runs a plain {@code /usr/bin/zsh}. So the control would have passed every test on the
+     * developer's Mac and protected nothing at all on the vhost it was being built for, in silence.
+     *
+     * <p>This runs {@code zsh -i} — no {@code -l} — so {@code .zprofile} and {@code .zlogin} are
+     * skipped exactly as they are on Linux. It therefore tests the Linux code path from a Mac,
+     * which is the only place we can currently run it. Reverting the scrub to {@code .zlogin} only
+     * makes this test fail while the login-shell test above still passes.
+     */
+    @Test
+    void scrubAlsoRunsInAnInteractiveNonLoginShell(@TempDir Path tmp) throws Exception {
+        assumeTrue(Files.isExecutable(ZSH), "/bin/zsh not present — nothing to prove here");
+        Path homeZshrc = Path.of(System.getProperty("user.home"), ".zshrc");
+        assumeTrue(Files.exists(homeZshrc), "$HOME/.zshrc does not exist — no real chain to test against");
+
+        Set<String> allowed = MemberEnvAllowList.derive(List.of());
+        Path zdotdir = EnvAllowListScrub.generate(tmp, allowed);
+
+        Map<String, String> cleanParent = Map.of(
+                "HOME", System.getProperty("user.home"),
+                "PATH", "/usr/bin:/bin",
+                "SHELL", "/bin/zsh",
+                "USER", System.getProperty("user.name", "nobody"),
+                "TMPDIR", tmp.toString());
+
+        List<String> interactiveOnly = List.of("-i");
+        Set<String> baseline = exportedNamesFromCleanParent(cleanParent, null, interactiveOnly);
+        Set<String> scrubbed = exportedNamesFromCleanParent(cleanParent, zdotdir, interactiveOnly);
+
+        Set<String> expected = new TreeSet<>();
+        for (String name : baseline) {
+            if (MemberEnvAllowList.keeps(allowed, name)) {
+                expected.add(name);
+            }
+        }
+        expected.add("ZDOTDIR"); // the harness set it and it is infrastructure, so it must survive
+        assertEquals(expected, scrubbed,
+                "a non-login interactive zsh is what a herdr pane runs on Linux; its surviving "
+                        + "exported names must EQUAL baseline \u2229 allow-list, exactly as for a login "
+                        + "shell. A difference here means the scrub is dead on Linux.");
+    }
+
+    /**
+     * Run {@code /bin/zsh -l -i} from a clean parent and return the NAMES it has exported by prompt
+     * time. With {@code zdotdir} non-null, {@code ZDOTDIR} points at a generated scrub directory, so
+     * the login chain ends in CB-633's scrub; null gives the un-scrubbed baseline.
+     */
+    private static Set<String> exportedNamesFromCleanParent(Map<String, String> cleanParent,
+                                                            Path zdotdir) throws IOException, InterruptedException {
+        return exportedNamesFromCleanParent(cleanParent, zdotdir, List.of("-l", "-i"));
+    }
+
+    private static Set<String> exportedNamesFromCleanParent(Map<String, String> cleanParent,
+                                                            Path zdotdir, List<String> shellFlags)
+            throws IOException, InterruptedException {
+        List<String> argv = new ArrayList<>();
+        argv.add("/bin/zsh");
+        argv.addAll(shellFlags);
+        ProcessBuilder pb = new ProcessBuilder(argv);
+        pb.environment().clear();
+        pb.environment().putAll(cleanParent);
+        if (zdotdir != null) {
+            pb.environment().put("ZDOTDIR", zdotdir.toAbsolutePath().toString());
+        }
+        pb.redirectError(ProcessBuilder.Redirect.DISCARD); // prompts and rc chatter, never data
+
+        Process zsh = pb.start();
+        // Names of exports whose VALUE is still non-empty. A blanked variable stays EXPORTED with
+        // an empty value ("NAME=") — that is the control working, not surviving — so plain
+        // `env | cut -d= -f1` would wrongly count blanked names as survivors.
+        String probeScript = "command env | awk -F= '/^[A-Za-z_][A-Za-z0-9_]*=/ && length($0) > "
+                + "length($1)+1 { print $1 }' | command sort -u\nexit\n";
+        zsh.getOutputStream().write(probeScript.getBytes(StandardCharsets.UTF_8));
+        zsh.getOutputStream().flush();
+
+        String stdout = new String(zsh.getInputStream().readAllBytes(), StandardCharsets.UTF_8);
+        assertTrue(zsh.waitFor(60, java.util.concurrent.TimeUnit.SECONDS),
+                "the probe login shell did not exit within 60s");
+        assertTrue(zsh.exitValue() == 0, "probe zsh exited non-zero — see test failure, values never printed");
+
+        Set<String> names = new HashSet<>();
+        for (String line : stdout.split("\n")) {
+            Matcher m = ENV_NAME.matcher(line.trim());
+            if (m.matches()) {
+                names.add(m.group(1));
+            }
+        }
+        return names;
+    }
+}

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

@@ -0,0 +1,170 @@
+package dev.ltms.fleet.member;
+
+import dev.ltms.fleet.config.FleetConfig;
+import dev.ltms.fleet.herdr.AgentControl;
+import dev.ltms.fleet.herdr.FakeHerdr;
+import dev.ltms.fleet.herdr.WorkspaceControl;
+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 java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+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;
+
+/**
+ * CB-633: proves the allow-list scrub is actually WIRED INTO the spawn path — not merely that its
+ * pieces work when a test calls them directly.
+ *
+ * <p>Why this test exists, and why it is separate from {@link EnvAllowListScrubTest}. Every other
+ * test of this feature calls {@code EnvAllowListScrub} or {@code MemberEnvAllowList} itself. Those
+ * prove the scrub is correct. None of them proves anyone runs it: deleting the single
+ * {@code applyEnvironmentAllowListPolicy(cfg, launch)} line from {@code spawnInternal} left all 896
+ * tests green while turning the control completely off. That is the recurring shape in this
+ * codebase — a feature behind one call, with every test on the far side of it (CB-586, CB-611).
+ *
+ * <p>So this test starts a real spawn through {@link HerdrPeerLauncher#spawn} and asserts on what
+ * reached herdr. It deliberately checks the pane-creation parameters rather than the launcher's own
+ * map, because the map is an intermediate: {@code ZDOTDIR} only protects anything if it is in the
+ * env herdr uses to create the pane, and that is the last point we can observe before the shell
+ * starts.
+ */
+class HerdrPeerLauncherAllowListWiringTest {
+
+    /** A name the daemon itself injects — it must survive its own scrub, so it must be allowed. */
+    private static final String INJECTED = "ANTHROPIC_BASE_URL";
+
+    @Test
+    void spawningUnderAllowListPolicyGivesThePaneAGeneratedZdotdir() {
+        FakeHerdr herdr = new FakeHerdr();
+        WiringLauncher launcher = new WiringLauncher(herdr, allowList());
+
+        launcher.spawn(new SpawnRequest("test", null, null, null, null, MemberRole.DEV));
+
+        String paneParams = String.valueOf(herdr.lastCall("pane.split").params());
+        assertTrue(paneParams.contains("ZDOTDIR"),
+                "the spawn must hand herdr a ZDOTDIR so the pane's zsh reads our generated startup "
+                        + "files; without it the scrub never runs and the member inherits the whole "
+                        + "host environment. pane.split params were: " + paneParams);
+
+        Path dir = Path.of(launcher.env.get("ZDOTDIR"));
+        assertTrue(Files.isDirectory(dir), "ZDOTDIR must point at a directory that exists: " + dir);
+        // Both startup files must exist and both must source the scrub: .zlogin covers macOS panes
+        // (login shells), .zshrc covers Linux panes (interactive, NOT login). Checking only one
+        // would pass on the platform it was written for and ship a dead control on the other.
+        for (String file : List.of(".zshrc", ".zlogin")) {
+            Path f = dir.resolve(file);
+            assertTrue(Files.isRegularFile(f), file + " must be generated: " + f);
+            assertTrue(readAll(f).contains(EnvAllowListScrub.SCRUB_FILE),
+                    file + " must source " + EnvAllowListScrub.SCRUB_FILE + " — a scrub only one of "
+                            + "them runs is dead on the platform that reads the other");
+        }
+        assertTrue(readAll(dir.resolve(EnvAllowListScrub.SCRUB_FILE)).contains(INJECTED),
+                "the allow-list must include the names this very launch injects (" + INJECTED
+                        + "), or the daemon's own configuration is blanked by its own control");
+    }
+
+    /** The default policy must not generate anything — an upgrade changes nothing until asked. */
+    @Test
+    void spawningUnderTheDefaultPolicyGeneratesNoZdotdir() {
+        FakeHerdr herdr = new FakeHerdr();
+        WiringLauncher launcher = new WiringLauncher(herdr, () -> new FleetConfig.MemberCredentials(
+                null, List.of(), List.of(), null));
+
+        launcher.spawn(new SpawnRequest("test", null, null, null, null, MemberRole.DEV));
+
+        assertFalse(launcher.env.containsKey("ZDOTDIR"),
+                "policy=deny-by-default is the shipped default; it must not silently start "
+                        + "rewriting members' shell startup files");
+    }
+
+    /**
+     * A non-zsh shell cannot read {@code ZDOTDIR} at all. The launcher must fall back rather than
+     * generate a directory nothing will ever read — a directory that would look like protection.
+     */
+    @Test
+    void aNonZshShellGeneratesNothingAndFallsBack() {
+        FakeHerdr herdr = new FakeHerdr();
+        WiringLauncher launcher = new WiringLauncher(herdr, allowList(), "/bin/bash");
+
+        launcher.spawn(new SpawnRequest("test", null, null, null, null, MemberRole.DEV));
+
+        assertFalse(launcher.env.containsKey("ZDOTDIR"),
+                "bash ignores ZDOTDIR; setting it would be protection theatre");
+    }
+
+    private static Supplier<FleetConfig.MemberCredentials> allowList() {
+        return () -> new FleetConfig.MemberCredentials(
+                FleetConfig.MemberCredentials.POLICY_ALLOW_LIST, List.of(), List.of(), null);
+    }
+
+    private static String readAll(Path p) {
+        try {
+            return Files.readString(p);
+        } catch (java.io.IOException e) {
+            throw new AssertionError("cannot read " + p, e);
+        }
+    }
+
+    private static FleetConfig.Profile profile() {
+        return new FleetConfig.Profile("test", "http://gx00.gw:8000", null, null,
+                "BRIDGED_WORKER_TOKEN", List.of("test"), "pane", null, null, null, null, null);
+    }
+
+    /**
+     * A minimal peer launcher whose {@code buildLaunch} returns a MUTABLE env map holding one name
+     * the daemon injects. Mutable on purpose: the policy adds {@code ZDOTDIR} to this very map, so
+     * an immutable one would throw and the test would pass for the wrong reason.
+     */
+    private static final class WiringLauncher extends HerdrPeerLauncher {
+        private final Map<String, String> env = new HashMap<>(Map.of(INJECTED, "http://gateway"));
+
+        WiringLauncher(FakeHerdr herdr, Supplier<FleetConfig.MemberCredentials> creds) {
+            this(herdr, creds, "/bin/zsh");
+        }
+
+        WiringLauncher(FakeHerdr herdr, Supplier<FleetConfig.MemberCredentials> creds, String shell) {
+            super("test", new AgentControl(herdr), new WorkspaceControl(herdr),
+                    Map.of("test", profile()), "test",
+                    name -> "SHELL".equals(name) ? shell : null,
+                    0, () -> 0L, () -> { }, null, creds);
+        }
+
+        @Override
+        protected Launch buildLaunch(FleetConfig.Profile cfg, LaunchSpec spec) {
+            return new Launch(env, List.of("test"));
+        }
+
+        @Override
+        public Set<Capability> capabilities() {
+            return Set.of();
+        }
+    }
+
+    /** The generated directory is a temp directory; make sure the test does not leave a pile. */
+    @Test
+    void theGeneratedDirectoryIsRemovedWhenThePaneIsStopped() {
+        FakeHerdr herdr = new FakeHerdr();
+        WiringLauncher launcher = new WiringLauncher(herdr, allowList());
+
+        var spawned = launcher.spawn(new SpawnRequest("test", null, null, null, null, MemberRole.DEV));
+        Path dir = Path.of(launcher.env.get("ZDOTDIR"));
+        assertNotNull(spawned, "spawn returned nothing");
+        assertTrue(Files.isDirectory(dir));
+
+        launcher.stop(spawned.id());
+
+        assertEquals(false, Files.exists(dir),
+                "stopping the pane must remove its generated ZDOTDIR: " + dir);
+    }
+}

bridged/src/test/java/dev/ltms/fleet/member/MemberEnvAllowListTest.java

@@ -0,0 +1,105 @@
+package dev.ltms.fleet.member;
+
+import dev.ltms.fleet.config.FleetConfig;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * CB-633: the allow-list a member's environment scrub enforces is DERIVED from what the launcher
+ * itself injects — never hand-typed. These tests pin the derivation: adding a profile can only
+ * widen the set (never break another spawn), and a name no profile references is not on it.
+ */
+class MemberEnvAllowListTest {
+
+    /** The 18-arg Profile ctor (back-compat + CB-511 {@code env} passthrough). */
+    private static FleetConfig.Profile profile(String name, String tokenEnv,
+                                               String gitTokenEnv, String gitHostEnv,
+                                               Map<String, String> env) {
+        return new FleetConfig.Profile(name, "http://gx00.gw:8000", null, null, tokenEnv,
+                List.of("claude"), null, null, null, null, null, null,
+                gitTokenEnv, gitHostEnv, FleetConfig.Profile.KIND_CLAUDE_CODE, env, 1.0f, 5);
+    }
+
+    @Test
+    void everyKeyOfEveryProfileEnvMapLandsOnTheDerivedList() {
+        FleetConfig.Profile p = profile("p", null, null, null,
+                Map.of("MY_TOOL_ENDPOINT", "http://10.0.0.1", "MY_TOOL_OPTION", "x"));
+
+        Set<String> derived = MemberEnvAllowList.derive(List.of(p));
+
+        assertTrue(derived.contains("MY_TOOL_ENDPOINT"));
+        assertTrue(derived.contains("MY_TOOL_OPTION"));
+    }
+
+    @Test
+    void everyProfileTokenEnvGitTokenEnvAndGitHostEnvNameLandsOnTheDerivedList() {
+        FleetConfig.Profile p = profile("p", "GATEWAY_TOKEN_FOR_P",
+                "WORKER_GITEA_TOKEN", "MY_GITEA_HOST", Map.of());
+
+        Set<String> derived = MemberEnvAllowList.derive(List.of(p));
+
+        assertTrue(derived.contains("GATEWAY_TOKEN_FOR_P"), "tokenEnv is a variable NAME held in config");
+        assertTrue(derived.contains("WORKER_GITEA_TOKEN"));
+        assertTrue(derived.contains("MY_GITEA_HOST"));
+    }
+
+    @Test
+    void aNameNoProfileReferencesIsNotOnTheDerivedList() {
+        Set<String> derived = MemberEnvAllowList.derive(List.of(
+                profile("p", "TOKEN_A", null, null, Map.of("KEY_A", "v"))));
+
+        assertFalse(derived.contains("SOME_SECRET_NOBODY_CONFIGURED"),
+                "a hand-typed-feeling name must not appear by magic");
+        assertFalse(derived.contains("CONFLUENCE_USERNAME"),
+                "the exact class of name pattern filters missed");
+    }
+
+    @Test
+    void infrastructurePassthroughNamesAreAlwaysOnTheDerivedList() {
+        for (String infra : new String[]{"PATH", "HOME", "TERM", "TMPDIR", "SHLVL", "ZDOTDIR"}) {
+            assertTrue(MemberEnvAllowList.INFRASTRUCTURE_PASSTHROUGH.contains(infra),
+                    infra + " is infrastructure, not a credential");
+            assertTrue(MemberEnvAllowList.derive(List.of()).contains(infra),
+                    "derived list holds infrastructure even with zero profiles");
+        }
+    }
+
+    /**
+     * The property the ticket hangs the design on: ADDING a profile only ever widens the set, so a
+     * new profile in bridged.yaml cannot break an existing spawn's scrub.
+     */
+    @Test
+    void addingAProfileOnlyWidensTheDerivedSetNeverShrinksIt() {
+        FleetConfig.Profile first = profile("first", "TOKEN_FIRST", null, null, Map.of("FIRST_KEY", "v"));
+        Set<String> before = MemberEnvAllowList.derive(List.of(first));
+
+        FleetConfig.Profile second = profile("second", "TOKEN_SECOND", "GIT_TOK", null,
+                Map.of("SECOND_KEY", "v"));
+        Set<String> after = MemberEnvAllowList.derive(List.of(first, second));
+
+        assertTrue(after.containsAll(before), "widening only");
+        assertTrue(after.containsAll(Set.of("TOKEN_SECOND", "GIT_TOK", "SECOND_KEY")));
+    }
+
+    /** {@code LC_*} categories are infrastructure by prefix; everything else needs an exact match. */
+    @Test
+    void keepsMatchesExactlyPlusTheLocalePrefixRule() {
+        Set<String> derived = MemberEnvAllowList.derive(List.of());
+
+        assertTrue(MemberEnvAllowList.keeps(derived, "LC_FOO"), "prefix rule lives here, not in the caller");
+        assertFalse(MemberEnvAllowList.keeps(derived, "LCD_VAR"),
+                "a name that merely STARTS with the prefix letters is not LC_*");
+        assertTrue(MemberEnvAllowList.keeps(Set.of("MINE"), "MINE"));
+        assertFalse(MemberEnvAllowList.keeps(Set.of(), "SSH_AUTH_SOCK"),
+                "the ssh-agent handle is kept ONLY by explicit config decision, never by this rule");
+        assertEquals("LC_*", MemberEnvAllowList.zshCasePattern(),
+                "the generated script's case pattern and this rule must not drift apart");
+    }
+}