fleetd #425: fleet_profiles' default and worktree provisioning must read live placement

fleet_profiles' "default" was CompositePeerLauncher.defaultProfile, a value
frozen at construction from cfg.effectiveDefaultProfile(). An unqualified
fleet_spawn instead resolves the dev pool live via defaultProfileFor(DEV) on
every call, so reordering fleet.developers and reloading changed where a
spawn landed without ever changing what fleet_profiles reported.

- CompositePeerLauncher.defaultProfile() now delegates to
  defaultProfileFor(MemberRole.DEV) -- the same live, reload-aware pool read
  placement already uses -- falling back to the frozen field only when no
  profiles are configured at all.
- PeerLauncher gains a default defaultProfileFor(MemberRole) method so a
  generic PeerLauncher reference can ask for a role's live default; the
  default implementation delegates to defaultProfile() for launchers with no
  pool concept of their own.
- SessionManager.acquireWithWorktree resolved a profile via
  launcher.defaultProfile() (DEV-only) to provision repoRoot/parityOverlay,
  then spawned with the original (possibly blank) profile, which re-resolves
  independently through placement -- for any non-DEV role, or across a config
  reload between the two reads, the two resolutions could disagree and
  provision a worktree for a profile the member never runs on. Fixed by
  resolving once, through defaultProfileFor(the caller's actual role), and
  reusing that same resolved name for repoRoot, parityOverlay, and the spawn
  itself. Trade-off: this path now spawns with an explicit profile rather
  than a blank one, so it loses CompositePeerLauncher's cross-candidate retry
  on PeerUnreachableException -- accepted because a worktree provisioned for
  the wrong backend is worse than a spawn that fails cleanly and can be
  retried.

Tests: CompositePeerLauncherTest (live dev-pool reorder + empty-pool
fallback), FleetProfilesLiveDefaultTest (drives FleetMcp.profilesView
directly), SessionManagerTest (worktree overlay follows a reorder, and a
non-DEV role's worktree spawn uses that role's pool, not DEV's).

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

@@ -380,8 +380,7 @@ public final class Fleetd {
                 .map(session -> exhaustedPatternsByProfile.get(session.profile()))
                 .orElse(null);
         log.info("backend-exhausted classification (CB-578 stage A): {}",
-                CompletionResolver.coverage("exhaustedPattern", cfg.profiles().keySet(),
-                        exhaustedPatternsByProfile.keySet()));
+                exhaustedPatternCoverageLine(cfg.profiles().keySet(), exhaustedPatternsByProfile.keySet()));
         // fleetd #201 Unit 5: classify a completion-fallback scrape that matches a profile's
         // configured backend-error refusal (a credential outage, a provider 5xx) as a backend error
         // rather than handing it back as a real answer. Compiled once at startup, keyed by profile
@@ -401,8 +400,7 @@ public final class Fleetd {
         BackendErrorPatternLookup backendErrorPatterns = backendErrorPatternLookup(sessions::roster,
                 errorPatternsByProfile);
         log.info("backend-error classification (fleetd #201 Unit 5): {}",
-                CompletionResolver.coverage("errorPattern", cfg.profiles().keySet(),
-                        errorPatternsByProfile.keySet()));
+                errorPatternCoverageLine(cfg.profiles().keySet(), errorPatternsByProfile.keySet()));
         // CB-578 stage B: on a classification that actually wins, quarantine the exhausted profile's
         // CREDENTIAL — not the profile name — so a profile sharing that credential (e.g. two models
         // on one OpenAI account) is refused too, not just the one that happened to report it. Reads
@@ -807,6 +805,41 @@ public final class Fleetd {
         }, quarantine, profile -> startupExhaustedPatterns.containsKey(profile));
     }
 
+    /**
+     * fleetd #415 (review follow-up): package-private factory for the CB-578 stage A {@code
+     * exhaustedPattern} startup coverage line, paired explicitly with {@link
+     * CompletionResolver.UnsetMeaning#OFF} — {@code exhaustedPattern} has no fallback, so a
+     * profile with none configured really does have the classification off.
+     *
+     * <p>Extracted out of {@code main} for the same reason {@link #capacitySource} and {@link
+     * #worktreeBranchLookup} were: {@code coverage()}'s own tests ({@code CompletionResolverTest})
+     * prove it words {@code OFF} and {@link CompletionResolver.UnsetMeaning#BUILT_IN_DEFAULT}
+     * correctly when a test supplies the meaning itself — they cannot prove {@code main} pairs the
+     * right meaning with the right key, which is the actual fleetd #415 defect. <b>Measured:</b>
+     * swapping the {@code UnsetMeaning} arguments between this method and {@link
+     * #errorPatternCoverageLine} — recreating #415's defect with the two keys exchanged — compiled
+     * with 0 errors and left all 1506 existing tests green before {@code
+     * FleetdPatternCoverageLineTest} was added to catch exactly that swap.
+     */
+    static String exhaustedPatternCoverageLine(Set<String> allProfiles, Set<String> configuredProfiles) {
+        return CompletionResolver.coverage("exhaustedPattern", CompletionResolver.UnsetMeaning.OFF,
+                allProfiles, configuredProfiles);
+    }
+
+    /**
+     * fleetd #415 (review follow-up): the {@code errorPattern} counterpart of {@link
+     * #exhaustedPatternCoverageLine}, paired explicitly with {@link
+     * CompletionResolver.UnsetMeaning#BUILT_IN_DEFAULT} — an unset {@code errorPattern} still runs
+     * backend-error classification against {@code CompletionResolver}'s built-in {@code
+     * BACKEND_ERROR} pattern, so the empty case is not "off". See {@link
+     * #exhaustedPatternCoverageLine}'s javadoc for the measured swap mutation this pairing guards
+     * against.
+     */
+    static String errorPatternCoverageLine(Set<String> allProfiles, Set<String> configuredProfiles) {
+        return CompletionResolver.coverage("errorPattern", CompletionResolver.UnsetMeaning.BUILT_IN_DEFAULT,
+                allProfiles, configuredProfiles);
+    }
+
     /**
      * fleetd #416: production source for {@code fleet_list}'s per-profile capacity facts.
      *

fleetd/src/main/java/dev/ltms/fleet/inject/CompletionResolver.java

@@ -698,17 +698,57 @@ public final class CompletionResolver implements TurnListener {
     }
 
     /**
-     * Coverage summary for the CB-578 stage A exhausted-pattern classification, logged at startup
+     * What an unset pattern key means for the classification it configures (fleetd#415).
+     * {@code coverage()} cannot infer this from the key's name — the two keys it currently
+     * describes disagree on it, and a string comparison on the name would just move the same bug
+     * to a new spot — so every caller must state it explicitly.
+     *
+     * <p><strong>This alone does not prove a caller passes the right one for its key.</strong> A
+     * test that calls {@code coverage()} directly and supplies the meaning itself only proves this
+     * enum is worded correctly, never that {@code Fleetd}'s two call sites pair each key with its
+     * true meaning — that pairing is #415's actual defect. Measured on review: swapping the two
+     * {@code UnsetMeaning} arguments at those call sites (giving {@code exhaustedPattern} the
+     * built-in-default wording and {@code errorPattern} the off wording — #415's exact defect with
+     * the keys exchanged) compiled with 0 errors and left all 1506 existing tests green. See
+     * {@code dev.ltms.fleet.Fleetd#exhaustedPatternCoverageLine}/{@code #errorPatternCoverageLine}
+     * and {@code FleetdPatternCoverageLineTest}, which exists specifically to catch that swap.
+     */
+    public enum UnsetMeaning {
+        /** No fallback exists: a profile with no configured pattern truly has this classification off. */
+        OFF,
+        /** A built-in pattern applies when unset: the classification still runs for that profile. */
+        BUILT_IN_DEFAULT
+    }
+
+    /**
+     * Coverage summary for a fleetd#201/CB-578-style pattern-key classification, logged at startup
      * the way {@link dev.ltms.fleet.health.FleetHealthMonitor#coverage} is — so an operator can
      * see whether the classification is on, and for which profiles, without reading every
      * profile's config by hand.
      *
+     * <p>fleetd#415: this method measures <em>pattern coverage</em> — how many profiles set the
+     * key — which is not the same thing as <em>feature state</em> for a key with a fallback. For
+     * {@code errorPattern}, an empty {@code configuredProfiles} still runs the classification
+     * against {@code CompletionResolver}'s built-in compatibility pattern ({@link #BACKEND_ERROR}
+     * at line ~84); for {@code exhaustedPattern} there is no fallback, so empty really does mean
+     * off. {@code unsetMeaning} is the single, required source of that fact — see
+     * {@link dev.ltms.fleet.config.FleetConfig#rejectMalformedProfilePatterns} lines ~2029-2032 for
+     * where it is documented for config authors. It is a required parameter, not a defaulted
+     * overload: a third pattern key added later must supply one to compile at all, rather than
+     * silently inheriting whichever wording this method happened to default to.
+     *
      * @param allProfiles        every configured profile name
-     * @param configuredProfiles the subset of {@code allProfiles} that carry an exhausted pattern
+     * @param configuredProfiles the subset of {@code allProfiles} that carry the pattern
      */
-    public static String coverage(String patternKey, Set<String> allProfiles, Set<String> configuredProfiles) {
+    public static String coverage(String patternKey, UnsetMeaning unsetMeaning, Set<String> allProfiles,
+                                   Set<String> configuredProfiles) {
         if (configuredProfiles.isEmpty()) {
-            return "off (no profile has an " + patternKey + " configured; profiles: " + sorted(allProfiles) + ")";
+            return switch (unsetMeaning) {
+                case OFF -> "off (no profile has an " + patternKey + " configured; profiles: "
+                        + sorted(allProfiles) + ")";
+                case BUILT_IN_DEFAULT -> "built-in default for all profiles (no profile customises "
+                        + patternKey + "; profiles: " + sorted(allProfiles) + ")";
+            };
         }
         Set<String> unconfigured = new TreeSet<>(allProfiles);
         unconfigured.removeAll(configuredProfiles);

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

@@ -508,8 +508,23 @@ public final class CompositePeerLauncher implements PeerLauncher {
         return known.isEmpty() ? List.copyOf(configured.keySet()) : known;
     }
 
-    /** The profile an unqualified spawn for {@code role} falls back to under {@code fixed} placement. */
-    private String defaultProfileFor(MemberRole role) {
+    /**
+     * {@inheritDoc}
+     *
+     * <p>Live: reads {@link #poolFor}, which reads {@link #profileConfigs} and {@link #fleet} fresh
+     * on every call, so a config reload is visible without a restart (fleetd #425) — unlike {@link
+     * #defaultProfile}, the field captured once at construction, which this falls back to only when
+     * {@link #poolFor} has nothing to offer at all (no profiles configured for this composite).
+     *
+     * <p>Exact only under the {@code fixed} placement policy — the one that reads this value
+     * ({@code FixedPlacementPolicy}, package-private, hence not linked) as its first, preferred
+     * candidate. {@code weighted}/{@code round-robin} placement can choose a different candidate
+     * from {@code role}'s pool even on the very first spawn; this method does not simulate that
+     * choice, matching what the {@code defaultProfile:}-derived reporting this replaces has always
+     * done.
+     */
+    @Override
+    public String defaultProfileFor(MemberRole role) {
         List<String> pool = poolFor(role);
         return pool.isEmpty() ? defaultProfile : pool.getFirst();
     }
@@ -647,9 +662,21 @@ public final class CompositePeerLauncher implements PeerLauncher {
         return byProfile.keySet();
     }
 
+    /**
+     * {@inheritDoc}
+     *
+     * <p>fleetd #425: reports the <em>live</em> {@code dev} pool's first entry — the same value
+     * {@link #defaultProfileFor} computes for {@link MemberRole#DEV} — not the {@link
+     * #defaultProfile} field captured at construction. An unqualified {@code fleet_spawn} defaults
+     * to {@code MemberRole#DEV} (see {@link dev.ltms.fleet.peer.SpawnRequest}), so "the dev pool's
+     * live first entry" is exactly the profile such a spawn actually lands on right now — the
+     * question {@code fleet_profiles}' {@code "default"} field exists to answer. The frozen field is
+     * a role-agnostic fallback used only when {@link #poolFor} has nothing to report at all (no
+     * profiles configured), which {@link #defaultProfileFor} already handles.
+     */
     @Override
     public String defaultProfile() {
-        return defaultProfile;
+        return defaultProfileFor(MemberRole.DEV);
     }
 
     /**

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

@@ -230,6 +230,26 @@ public final class ReplyPushLoop {
                 .collect(Collectors.toUnmodifiableSet());
     }
 
+    /**
+     * Test seam only (fleetd #418): carries no production behaviour, and nothing in this class
+     * calls it. Exposes {@link #pendingQuestionTurnIdsFor} — the exact state {@link #decide} reads
+     * to decide whether a question keeps a lead's schedule alive.
+     *
+     * <p>{@code MessageService.ask()} does three things in order before a question is fully open to
+     * this loop: it flips the ticket's {@code poll()} phase to {@code Phase.ASKING}, then resolves
+     * the reverse-rendezvous waiter, then calls {@link #onQuestionOpened}, which is what actually
+     * populates {@link #pendingQuestions}. A test that barriers on {@code Phase.ASKING} observes only
+     * the first of those three steps — under load the asker thread can be descheduled between steps
+     * one and three, so the barrier releases before this method's underlying map is populated, and
+     * {@link #decide} correctly reports nothing pending yet. A test that must order itself after the
+     * state {@link #decide} actually reads waits on this instead of on the phase.
+     *
+     * @return an unmodifiable snapshot; empty for a lead with no open questions
+     */
+    Set<String> pendingQuestionTurnIdsForTest(String lead) {
+        return pendingQuestionTurnIdsFor(lead);
+    }
+
     private List<PendingIncident> pendingIncidentsFor(String lead) {
         return pendingIncidents.values().stream().filter(i -> lead.equals(i.key().lead())).toList();
     }

fleetd/src/main/java/dev/ltms/fleet/peer/PeerLauncher.java

@@ -143,9 +143,34 @@ public interface PeerLauncher {
 
     /**
      * The profile a no-argument {@link #spawn(SpawnRequest)} uses, or {@code null} if none is configured.
+     *
+     * <p>fleetd #425: for an implementation with role pools (a no-argument spawn is read as {@link
+     * MemberRole#DEV}, see {@link SpawnRequest}), this must be the profile a live spawn of that role
+     * would actually be placed on right now, not a value captured once at startup — a caller such as
+     * {@code fleet_profiles} relies on this to report a live, not frozen, fact.
      */
     String defaultProfile();
 
+    /**
+     * The profile an unqualified spawn of {@code role} would resolve to right now — the role-aware,
+     * live counterpart of {@link #defaultProfile()} (fleetd #425).
+     *
+     * <p>A caller that must provision something profile-specific (working directory, parity overlay
+     * files) <em>before</em> the actual spawn — {@code SessionManager.acquireWithWorktree} is the one
+     * that exists today — needs the exact profile that spawn will use, for the caller's real role,
+     * not a role-agnostic guess. Calling {@link #defaultProfile()} for that purpose reads {@code
+     * MemberRole#DEV}'s answer regardless of the caller's actual role, which is wrong for any other
+     * role and can provision for a profile the spawn never lands on.
+     *
+     * <p>Default implementation returns {@link #defaultProfile()}, ignoring {@code role} — the right
+     * answer for a launcher with no role-pool concept of its own (e.g. a single {@code
+     * HerdrPeerLauncher} adapter, which is never reached this way in production: {@code
+     * CompositePeerLauncher} always fronts it and resolves roles itself).
+     */
+    default String defaultProfileFor(MemberRole role) {
+        return defaultProfile();
+    }
+
     /**
      * Resolve the effective working directory for a spawn {@code req} without actually spawning.
      * Resolution order: requestedCwd → profile cwd → callerCwd → daemon cwd.

fleetd/src/main/java/dev/ltms/fleet/session/SessionManager.java

@@ -584,8 +584,21 @@ public final class SessionManager implements TurnListener {
                                               String ownerTerminal, WorktreeRequest wt,
                                                String sessionName, String resumeSessionId,
                                                MemberLifecycle.SlotReservation reservation) {
+        // fleetd #425: resolved through the role's live pool (launcher.defaultProfileFor(memberRole)),
+        // never launcher.defaultProfile() — that answers for MemberRole.DEV only, and a worktree spawn
+        // can be for any role. This same resolved name is reused below for repoRoot, parityOverlay,
+        // AND the spawn itself (an explicit profile, not a blank one) so the worktree is always
+        // provisioned for the profile the member actually runs on. Before this fix the two could
+        // disagree: this name picked repoRoot/overlay, but the spawn below passed the ORIGINAL
+        // (blank) profile through to placement, which re-resolves live and can pick a different
+        // profile if the pool changed between the two reads, or a genuinely different one under
+        // weighted/round-robin placement. The cost is that an unqualified worktree-provisioned spawn
+        // no longer gets CompositePeerLauncher's cross-candidate retry on PeerUnreachableException —
+        // it is now a single explicit-profile spawn, same as one where the caller names a profile.
+        // That trade is deliberate: a worktree provisioned for the wrong backend (the #425 hazard) is
+        // worse than a spawn that fails cleanly and can be retried by the caller.
         String preResolvedProfile = (profile == null || profile.isBlank())
-                ? launcher.defaultProfile() : profile;
+                ? launcher.defaultProfileFor(memberRole) : profile;
         // CB-507: resolve through the launcher's CB-112 chain (requested → profile cwd → caller →
         // daemon cwd → "."), never the raw args. A plain REST spawn supplies neither a requested
         // nor a caller cwd, so taking the first non-blank of those two yielded null and put
@@ -608,7 +621,10 @@ public final class SessionManager implements TurnListener {
             // copies more files into the worktree after add() returns, so sharing the group any earlier
             // leaves those overlay files operator-owned and read-only for a different-uid member.
             worktrees.shareWithGroup(repoRoot, path);
-            handle = launcher.spawn(new SpawnRequest(profile, path, callerCwd, sessionName, resumeSessionId, memberRole));
+            // fleetd #425: preResolvedProfile, not the original (possibly blank) profile — see the
+            // comment above where it is resolved. The overlay/repoRoot above and the spawn here must
+            // name the same profile.
+            handle = launcher.spawn(new SpawnRequest(preResolvedProfile, path, callerCwd, sessionName, resumeSessionId, memberRole));
         } catch (RuntimeException e) {
             log.warn("spawn failed for profile={} role={} branch={} path={}: {}",
                     preResolvedProfile, memberRole, branch, path, e.getMessage());
@@ -636,7 +652,7 @@ public final class SessionManager implements TurnListener {
             }
             throw e;
         }
-        String resolvedProfile = resolveProfile(handle, profile);
+        String resolvedProfile = resolveProfile(handle, preResolvedProfile);
         String cwd = launcher.effectiveCwd(new SpawnRequest(resolvedProfile, path, callerCwd));
         long now = nowNanos.getAsLong();
         // CB-619: see the no-worktree path above — bind before recording, and store the returned

fleetd/src/test/java/dev/ltms/fleet/FleetdPatternCoverageLineTest.java

@@ -0,0 +1,67 @@
+package dev.ltms.fleet;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.util.Set;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+
+/**
+ * fleetd #415 (review follow-up): {@code CompletionResolverTest} proves {@code coverage()} words
+ * {@code UnsetMeaning.OFF} and {@code UnsetMeaning.BUILT_IN_DEFAULT} correctly — but every one of
+ * those tests supplies the meaning itself. That proves the enum's wording, never that {@code
+ * Fleetd} pairs the right meaning with the right pattern key. That pairing is #415's actual
+ * defect: {@code coverage()} had no way to know what unset meant for its key, so the fix moved
+ * the fact to the caller — and nothing yet proved the caller states it correctly.
+ *
+ * <p><b>Measured or it didn't happen:</b> swapping the two {@code UnsetMeaning} arguments at
+ * {@code Fleetd}'s two coverage call sites — giving {@code exhaustedPattern} the built-in-default
+ * wording and {@code errorPattern} the off wording, #415's exact defect with the keys exchanged —
+ * compiled with 0 errors and left all 1506 existing tests green. This class exists to turn that
+ * swap red.
+ *
+ * <p>It calls {@link Fleetd#exhaustedPatternCoverageLine} and {@link Fleetd#errorPatternCoverageLine}
+ * directly rather than reading {@code Fleetd.java} as source text (the shape {@code
+ * FleetdCompletionResolverWiringTest} uses for a different wiring gap): those two methods are the
+ * extracted call sites {@code main} actually invokes, following the same {@code static} factory +
+ * dedicated-test pattern as {@link Fleetd#capacitySource} and {@link Fleetd#worktreeBranchLookup}.
+ */
+class FleetdPatternCoverageLineTest {
+
+    private static final Set<String> PROFILES = Set.of("terra", "gx10");
+
+    @Test
+    @DisplayName("exhaustedPatternCoverageLine says off when no profile configures exhaustedPattern")
+    void exhaustedPatternCoverageLineSaysOffWhenNoProfileConfiguresIt() {
+        assertEquals("off (no profile has an exhaustedPattern configured; profiles: [gx10, terra])",
+                Fleetd.exhaustedPatternCoverageLine(PROFILES, Set.of()));
+    }
+
+    @Test
+    @DisplayName("errorPatternCoverageLine says built-in default when no profile configures errorPattern")
+    void errorPatternCoverageLineSaysBuiltInDefaultWhenNoProfileConfiguresIt() {
+        assertEquals("built-in default for all profiles (no profile customises errorPattern; "
+                        + "profiles: [gx10, terra])",
+                Fleetd.errorPatternCoverageLine(PROFILES, Set.of()));
+    }
+
+    @Test
+    @DisplayName("the two keys produce different wording for the identical empty-coverage input")
+    void theTwoKeysProduceDifferentWordingForTheSameEmptyInput() {
+        String exhaustedLine = Fleetd.exhaustedPatternCoverageLine(PROFILES, Set.of());
+        String errorLine = Fleetd.errorPatternCoverageLine(PROFILES, Set.of());
+
+        // Pinned individually above; restated here so this test alone still catches a swap even
+        // if one of the two tests above were ever deleted.
+        assertEquals("off (no profile has an exhaustedPattern configured; profiles: [gx10, terra])",
+                exhaustedLine);
+        assertEquals("built-in default for all profiles (no profile customises errorPattern; "
+                        + "profiles: [gx10, terra])", errorLine);
+        assertNotEquals(exhaustedLine, errorLine,
+                "swapping which UnsetMeaning pairs with which pattern key at Fleetd's call sites "
+                        + "must be caught here — that pairing, not coverage()'s own wording in isolation, "
+                        + "is fleetd #415's actual defect");
+    }
+}

fleetd/src/test/java/dev/ltms/fleet/inject/CompletionResolverTest.java

@@ -20,6 +20,7 @@ import java.util.regex.Pattern;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /** Unit behaviour of the CB-106 completion resolver in isolation from the injector. */
@@ -884,19 +885,22 @@ class CompletionResolverTest {
     @Test
     void coverageIsOffWhenNoProfileHasAPatternConfigured() {
         assertEquals("off (no profile has an exhaustedPattern configured; profiles: [terra])",
-                CompletionResolver.coverage("exhaustedPattern", Set.of("terra"), Set.of()));
+                CompletionResolver.coverage("exhaustedPattern", CompletionResolver.UnsetMeaning.OFF,
+                        Set.of("terra"), Set.of()));
     }
 
     @Test
     void coverageIsFullWhenEveryProfileHasAPatternConfigured() {
         assertEquals("full (all profiles configured: [gx10, terra])",
-                CompletionResolver.coverage("exhaustedPattern", Set.of("terra", "gx10"), Set.of("terra", "gx10")));
+                CompletionResolver.coverage("exhaustedPattern", CompletionResolver.UnsetMeaning.OFF,
+                        Set.of("terra", "gx10"), Set.of("terra", "gx10")));
     }
 
     @Test
     void coverageIsPartialAndNamesWhichProfilesAreConfigured() {
         assertEquals("partial (configured: [terra]; not configured: [gx10])",
-                CompletionResolver.coverage("exhaustedPattern", Set.of("terra", "gx10"), Set.of("terra")));
+                CompletionResolver.coverage("exhaustedPattern", CompletionResolver.UnsetMeaning.OFF,
+                        Set.of("terra", "gx10"), Set.of("terra")));
     }
 
     /**
@@ -910,11 +914,42 @@ class CompletionResolverTest {
      *
      * <p>Every earlier test here passed the exhaustion case only, so none of them could see it. This
      * one pins that the message names the key the caller actually meant.
+     *
+     * <p>fleetd#415: the expected wording changed here too. {@code errorPattern} has a built-in
+     * fallback ({@link CompletionResolver#BACKEND_ERROR}), so an empty {@code configuredProfiles}
+     * for it is not "off" — see {@link #coverageDistinguishesOffFromBuiltInDefaultForTheSameEmptyInput}
+     * for the test built specifically to pin that distinction.
      */
     @Test
     void coverageNamesTheConfigKeyItsCallerMeansRatherThanAlwaysSayingExhaustedPattern() {
-        assertEquals("off (no profile has an errorPattern configured; profiles: [gx10, terra])",
-                CompletionResolver.coverage("errorPattern", Set.of("terra", "gx10"), Set.of()));
+        assertEquals("built-in default for all profiles (no profile customises errorPattern; "
+                        + "profiles: [gx10, terra])",
+                CompletionResolver.coverage("errorPattern", CompletionResolver.UnsetMeaning.BUILT_IN_DEFAULT,
+                        Set.of("terra", "gx10"), Set.of()));
+    }
+
+    /**
+     * fleetd#415: {@code coverage()} measures pattern coverage (how many profiles set the key), but
+     * for {@code errorPattern} the empty case is not the feature-off state — a profile with no
+     * configured {@code errorPattern} still runs the classification against
+     * {@link CompletionResolver#BACKEND_ERROR}. For {@code exhaustedPattern} there is no fallback,
+     * so empty really is off. Same shape of input (empty {@code configuredProfiles}, one profile),
+     * different {@link CompletionResolver.UnsetMeaning} — the wording must differ, or this method is
+     * back to conflating pattern coverage with feature state for the one key where they disagree.
+     */
+    @Test
+    void coverageDistinguishesOffFromBuiltInDefaultForTheSameEmptyInput() {
+        String exhaustedLine = CompletionResolver.coverage("exhaustedPattern",
+                CompletionResolver.UnsetMeaning.OFF, Set.of("gx10", "terra"), Set.of());
+        String errorLine = CompletionResolver.coverage("errorPattern",
+                CompletionResolver.UnsetMeaning.BUILT_IN_DEFAULT, Set.of("gx10", "terra"), Set.of());
+
+        assertEquals("off (no profile has an exhaustedPattern configured; profiles: [gx10, terra])",
+                exhaustedLine);
+        assertEquals("built-in default for all profiles (no profile customises errorPattern; "
+                        + "profiles: [gx10, terra])", errorLine);
+        assertNotEquals(exhaustedLine, errorLine,
+                "the same empty-coverage input must not read as the same feature state for both keys");
     }
 
     // --- fleetd#201 Unit 1: target-keyed backend-error pattern + typed sink ----------------------

fleetd/src/test/java/dev/ltms/fleet/mcp/FleetProfilesLiveDefaultTest.java

@@ -0,0 +1,114 @@
+package dev.ltms.fleet.mcp;
+
+import dev.ltms.fleet.config.ConfigRef;
+import dev.ltms.fleet.config.FleetConfig;
+import dev.ltms.fleet.guard.SubscriptionGuard;
+import dev.ltms.fleet.herdr.AgentControl;
+import dev.ltms.fleet.herdr.FakeHerdr;
+import dev.ltms.fleet.herdr.WorkspaceControl;
+import dev.ltms.fleet.member.ClaudeCodeLauncher;
+import dev.ltms.fleet.member.CompositePeerLauncher;
+import dev.ltms.fleet.peer.MemberRole;
+import dev.ltms.fleet.peer.PeerLauncher;
+import dev.ltms.fleet.peer.SpawnRequest;
+import dev.ltms.fleet.placement.BackendQuarantine;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+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.assertTrue;
+
+/**
+ * fleetd #425: {@code fleet_profiles}' {@code "default"} field was captured once at boot
+ * ({@code cfg.effectiveDefaultProfile()}, frozen into {@code CompositePeerLauncher.defaultProfile}
+ * at construction) while an unqualified spawn resolves the same underlying key
+ * ({@code fleet.developers}' first entry) live, on every call. Reordering {@code fleet.developers}
+ * and reloading changed where a spawn landed without ever changing what {@code fleet_profiles}
+ * reported — a lead following {@code CLAUDE.md}'s "check {@code fleet_profiles} once per session"
+ * instruction was told a stale answer.
+ *
+ * <p>This test drives the exact caller {@code fleet_profiles} uses —
+ * {@link FleetMcp#profilesView(PeerLauncher, FleetMcp.QuarantineSource, FleetMcp.OutageSource)} —
+ * against a real, reloadable {@link ConfigRef}, so it fails if the reporting path is ever recoupled
+ * to a frozen value instead of {@link CompositePeerLauncher#defaultProfile()}'s live answer.
+ */
+class FleetProfilesLiveDefaultTest {
+
+    /** A minimal fleetd.yaml whose dev pool is {@code profilesInOrder}, in that definition order. */
+    private static String yamlWithDevPool(String... profilesInOrder) {
+        StringBuilder devPool = new StringBuilder();
+        for (int i = 0; i < profilesInOrder.length; i++) {
+            devPool.append("    slot").append(i).append(":\n      profile: ")
+                    .append(profilesInOrder[i]).append('\n');
+        }
+        return """
+                bind:
+                  host: 127.0.0.1
+                  port: 8765
+                herdrSocket: ~/.config/herdr/herdr.sock
+                profiles:
+                  opus:
+                    baseUrl: http://gx00.gw:8000
+                    model: opus-coder
+                  sonnet:
+                    baseUrl: http://gx00.gw:8000
+                    model: sonnet-coder
+                guard:
+                  offSubscriptionHosts:
+                    - gx00.gw
+                fleet:
+                  developers:
+                """ + devPool;
+    }
+
+    @Test
+    void fleetProfilesDefaultTracksALiveDevPoolReorderAfterReload(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("fleetd.yaml");
+        Files.writeString(f, yamlWithDevPool("opus", "sonnet"));
+        ConfigRef ref = new ConfigRef(f, FleetConfig.load(f));
+
+        Map<String, FleetConfig.Profile> profiles = Map.of(
+                "opus", new FleetConfig.Profile("opus", "http://gx00.gw:8000", "opus-coder", null,
+                        "FLEETD_WORKER_TOKEN", List.of("claude"), "tab", "fleetd-workers",
+                        "worker: {profile} #{n}", null, null, null),
+                "sonnet", new FleetConfig.Profile("sonnet", "http://gx00.gw:8000", "sonnet-coder", null,
+                        "FLEETD_WORKER_TOKEN", List.of("claude"), "tab", "fleetd-workers",
+                        "worker: {profile} #{n}", null, null, null));
+        FakeHerdr herdr = new FakeHerdr();
+        ClaudeCodeLauncher adapter = new ClaudeCodeLauncher(new AgentControl(herdr), new WorkspaceControl(herdr),
+                new SubscriptionGuard(Set.of("gx00.gw")), profiles, "opus", _ -> null);
+        PeerLauncher workers = new CompositePeerLauncher(
+                List.of(adapter), "opus", ref, _ -> 0, BackendQuarantine.none());
+
+        assertReportedDefaultMatchesAnUnqualifiedSpawn(workers, "opus");
+
+        Files.writeString(f, yamlWithDevPool("sonnet", "opus"));
+        ConfigRef.Outcome out = ref.reload();
+        assertTrue(out.applied(), () -> "reload should apply cleanly: " + out.error());
+
+        assertReportedDefaultMatchesAnUnqualifiedSpawn(workers, "sonnet");
+    }
+
+    /**
+     * Asserts BOTH that {@code fleet_profiles}' {@code "default"} equals {@code expected}, AND that
+     * it equals what a real unqualified {@code MemberRole#DEV} spawn actually gets placed on right
+     * now — the two facts fleetd #425 found disagreeing.
+     */
+    private static void assertReportedDefaultMatchesAnUnqualifiedSpawn(PeerLauncher workers, String expected) {
+        Map<String, Object> view = FleetMcp.profilesView(
+                workers, FleetMcp.QuarantineSource.none(), FleetMcp.OutageSource.none());
+        assertEquals(expected, view.get("default"),
+                "fleet_profiles' \"default\" must be the live dev-pool answer, not a boot-time snapshot");
+
+        String placed = workers.spawn(
+                new SpawnRequest(null, null, null, null, null, MemberRole.DEV)).profile();
+        assertEquals(expected, placed,
+                "sanity: the profile an unqualified dev spawn actually lands on");
+    }
+}

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

@@ -3,6 +3,7 @@ package dev.ltms.fleet.member;
 import ch.qos.logback.classic.Logger;
 import ch.qos.logback.classic.spi.ILoggingEvent;
 import ch.qos.logback.core.read.ListAppender;
+import dev.ltms.fleet.config.ConfigRef;
 import dev.ltms.fleet.config.FleetConfig;
 import dev.ltms.fleet.guard.SubscriptionGuard;
 import dev.ltms.fleet.herdr.Agent;
@@ -22,8 +23,11 @@ import dev.ltms.fleet.placement.BackendQuarantine;
 import dev.ltms.fleet.placement.PlacementException;
 import dev.ltms.fleet.placement.PlacementPolicies;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
 import org.slf4j.LoggerFactory;
 
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.EnumSet;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
@@ -908,6 +912,89 @@ class CompositePeerLauncherTest {
         assertTrue(e.getMessage().contains("maxLoad"), e.getMessage());
     }
 
+    // ── fleetd #425: defaultProfile()/defaultProfileFor() must track a live reload ─────────────
+
+    /** A minimal fleetd.yaml whose dev pool is {@code profilesInOrder}, in that definition order. */
+    private static String yamlWithDevPool(String... profilesInOrder) {
+        StringBuilder devPool = new StringBuilder();
+        for (int i = 0; i < profilesInOrder.length; i++) {
+            devPool.append("    slot").append(i).append(":\n      profile: ")
+                    .append(profilesInOrder[i]).append('\n');
+        }
+        return """
+                bind:
+                  host: 127.0.0.1
+                  port: 8765
+                herdrSocket: ~/.config/herdr/herdr.sock
+                profiles:
+                  opus:
+                    baseUrl: http://gx00.gw:8000
+                    model: opus-coder
+                  sonnet:
+                    baseUrl: http://gx00.gw:8000
+                    model: sonnet-coder
+                guard:
+                  offSubscriptionHosts:
+                    - gx00.gw
+                fleet:
+                  developers:
+                """ + devPool;
+    }
+
+    /**
+     * Criterion 1 (fleetd #425): reorder {@code fleet.developers}, reload, and assert the reported
+     * default ({@link CompositePeerLauncher#defaultProfile()} — what {@code fleet_profiles}' {@code
+     * "default"} is built from, see {@code FleetMcp.profilesView}) matches what an unqualified
+     * {@code MemberRole#DEV} spawn is actually placed on, both before and after the reorder. Asserts
+     * {@code applied()} so the test proves the reload actually took, not that nothing changed.
+     */
+    @Test
+    void defaultProfileTracksALiveDevPoolReorderAfterReload(@TempDir Path dir) throws Exception {
+        Path f = dir.resolve("fleetd.yaml");
+        Files.writeString(f, yamlWithDevPool("opus", "sonnet"));
+        ConfigRef ref = new ConfigRef(f, FleetConfig.load(f));
+
+        FakeHerdr herdr = new FakeHerdr();
+        StubLauncher adapter = new StubLauncher("claude", herdr, threeProfiles(), "opus", Set.of());
+        CompositePeerLauncher composite = new CompositePeerLauncher(
+                List.of(adapter), "opus", ref, _ -> 0, BackendQuarantine.none());
+
+        assertEquals("opus", composite.defaultProfile(),
+                "reported default starts at the dev pool's first entry");
+        assertEquals("opus", composite.spawn(
+                        new SpawnRequest(null, null, null, null, null, MemberRole.DEV)).profile(),
+                "an unqualified dev spawn must land on the same profile that was just reported");
+
+        Files.writeString(f, yamlWithDevPool("sonnet", "opus"));
+        ConfigRef.Outcome out = ref.reload();
+        assertTrue(out.applied(), () -> "reload should apply cleanly: " + out.error());
+
+        assertEquals("sonnet", composite.defaultProfile(),
+                "the reported default must follow the reorder with no daemon restart");
+        assertEquals("sonnet", composite.spawn(
+                        new SpawnRequest(null, null, null, null, null, MemberRole.DEV)).profile(),
+                "and it must still be exactly what an unqualified spawn actually gets");
+    }
+
+    /**
+     * Criterion 2 — the mirror, and the load-bearing half (fleetd #425): with NOTHING configured (no
+     * profiles at all, hence an empty pool for every role), the frozen {@code defaultProfile} field
+     * is still what gets reported. A fix that always returns {@code poolFor(role).getFirst()} with no
+     * empty-pool fallback throws or returns the wrong thing here even though criterion 1 above still
+     * passes — this is the test that catches it.
+     */
+    @Test
+    void defaultProfileFallsBackToTheFrozenFieldWhenNothingIsConfiguredAtAll() {
+        FakeHerdr herdr = new FakeHerdr();
+        StubLauncher adapter = new StubLauncher("claude", herdr, Map.of(), "opus", Set.of());
+        CompositePeerLauncher composite = new CompositePeerLauncher(
+                List.of(adapter), "opus", Map.of(), PlacementPolicies.fixed(), _ -> 0);
+
+        assertEquals("opus", composite.defaultProfile(),
+                "with no profiles configured at all, the frozen field is the only answer available");
+        assertEquals("opus", composite.defaultProfileFor(MemberRole.DEV));
+    }
+
     // ── CB-578 stage B: a BACKEND_EXHAUSTED classification quarantines the credential ──────────
 
     @Test

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

@@ -1802,7 +1802,11 @@ class MessageServiceTest {
             Thread asker = new Thread(() -> assertThrows(IllegalStateException.class,
                     () -> service.ask(T, "which config file?", 30_000)));
             asker.start();
-            awaitTicketPhaseOn(service, ticket, MessageService.Phase.ASKING);
+            // Phase.ASKING (markAsyncQuestion) is only the FIRST of ask()'s three steps; the assertion
+            // below depends on the THIRD (pushLoop.onQuestionOpened). Barrier on the push loop's own
+            // pending-question state instead of the phase — see ReplyPushLoop#pendingQuestionTurnIdsForTest.
+            MessageService.TaskView asking = awaitTicketPhaseOn(service, ticket, MessageService.Phase.ASKING);
+            awaitQuestionPendingOn(pushLoop, LEAD, asking.turnId());
             assertEquals(ReplyPushLoop.Action.INJECT, pushLoop.decide(LEAD, 0, 0, 0),
                     "the open question should be the one thing keeping this lead's schedule alive");
 
@@ -2094,6 +2098,26 @@ class MessageServiceTest {
         }
     }
 
+    /**
+     * fleetd #418: waits until {@code turnId} actually appears in {@code pushLoop}'s own open-question
+     * state for {@code lead} — {@link ReplyPushLoop#pendingQuestionTurnIdsForTest} — rather than until
+     * {@link MessageService#poll} reports {@link MessageService.Phase#ASKING}. {@code Phase.ASKING} is
+     * set by {@code markAsyncQuestion}, the FIRST of three steps {@code MessageService.ask()} performs;
+     * {@code pushLoop.onQuestionOpened} (the one that actually publishes to {@code pendingQuestions})
+     * is the THIRD. Under load the asker thread can be descheduled between those two steps, so a
+     * barrier on the phase alone can release before the push loop has anything pending — a test that
+     * then asserts on {@link ReplyPushLoop#decide} is asserting on state that has not been published
+     * yet, not on the throwing path it is named for.
+     */
+    private void awaitQuestionPendingOn(ReplyPushLoop pushLoop, String lead, String turnId) throws Exception {
+        long deadline = System.currentTimeMillis() + 3000;
+        while (!pushLoop.pendingQuestionTurnIdsForTest(lead).contains(turnId)) {
+            assertTrue(System.currentTimeMillis() < deadline,
+                    "turnId " + turnId + " never appeared in the push loop's pending questions for " + lead);
+            Thread.sleep(5);
+        }
+    }
+
     // --- CB-640: fleet health evidence accessors --------------------------------------------
 
     @Test

fleetd/src/test/java/dev/ltms/fleet/session/SessionManagerTest.java

@@ -6,12 +6,14 @@ import ch.qos.logback.classic.spi.ILoggingEvent;
 import ch.qos.logback.core.read.ListAppender;
 import dev.ltms.fleet.auth.MemberRegistry;
 import dev.ltms.fleet.auth.MemberLifecycle;
+import dev.ltms.fleet.config.ConfigRef;
 import dev.ltms.fleet.config.FleetConfig;
 import dev.ltms.fleet.guard.SubscriptionGuard;
 import dev.ltms.fleet.herdr.AgentControl;
 import dev.ltms.fleet.herdr.FakeHerdr;
 import dev.ltms.fleet.herdr.WorkspaceControl;
 import dev.ltms.fleet.member.ClaudeCodeLauncher;
+import dev.ltms.fleet.member.CompositePeerLauncher;
 import dev.ltms.fleet.msg.TestTurnTokens;
 import dev.ltms.fleet.peer.Capability;
 import dev.ltms.fleet.peer.CharterReceipt;
@@ -20,9 +22,14 @@ import dev.ltms.fleet.peer.PeerHandle;
 import dev.ltms.fleet.peer.PeerLauncher;
 import dev.ltms.fleet.peer.PeerUnreachableException;
 import dev.ltms.fleet.peer.SpawnRequest;
+import dev.ltms.fleet.placement.BackendQuarantine;
+import dev.ltms.fleet.placement.PlacementPolicies;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
 import org.slf4j.LoggerFactory;
 
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -1991,4 +1998,121 @@ class SessionManagerTest {
         sessions.rosterResolved();
         assertEquals(2, handle.callCount(), "once resolved, the id must not be looked up again");
     }
+
+    // ── fleetd #425 criterion 3: acquireWithWorktree must provision for the profile it actually
+    // spawns, never a name resolved before a live pool change is accounted for ────────────────────
+
+    /** Two profiles with distinct {@code cwd}/{@code parityOverlay}, and a dev pool of {@code first,second}. */
+    private static String worktreeReorderYaml(String first, String second) {
+        return """
+                bind:
+                  host: 127.0.0.1
+                  port: 8765
+                herdrSocket: ~/.config/herdr/herdr.sock
+                profiles:
+                  a:
+                    baseUrl: http://gx00.gw:8000
+                    model: coder-a
+                  b:
+                    baseUrl: http://gx00.gw:8000
+                    model: coder-b
+                guard:
+                  offSubscriptionHosts:
+                    - gx00.gw
+                fleet:
+                  developers:
+                    slot0:
+                      profile: %s
+                    slot1:
+                      profile: %s
+                """.formatted(first, second);
+    }
+
+    @Test
+    void acquireWithWorktreeProvisionsTheOverlayForTheProfileActuallySpawned(
+            @TempDir Path dir) throws Exception {
+        Path f = dir.resolve("fleetd.yaml");
+        Files.writeString(f, worktreeReorderYaml("a", "b"));
+        ConfigRef ref = new ConfigRef(f, FleetConfig.load(f));
+
+        Map<String, FleetConfig.Profile> profiles = Map.of(
+                "a", new FleetConfig.Profile("a", "http://gx00.gw:8000", "coder-a", null,
+                        "FLEETD_WORKER_TOKEN", List.of("claude"), "tab", "fleetd-workers",
+                        "worker: {profile} #{n}", null, "/repo/a", List.of("a.mcp.json")),
+                "b", new FleetConfig.Profile("b", "http://gx00.gw:8000", "coder-b", null,
+                        "FLEETD_WORKER_TOKEN", List.of("claude"), "tab", "fleetd-workers",
+                        "worker: {profile} #{n}", null, "/repo/b", List.of("b.mcp.json")));
+        FakeHerdr herdr = new FakeHerdr();
+        ClaudeCodeLauncher adapter = new ClaudeCodeLauncher(new AgentControl(herdr), new WorkspaceControl(herdr),
+                new SubscriptionGuard(Set.of("gx00.gw")), profiles, "a", _ -> null);
+        PeerLauncher launcher = new CompositePeerLauncher(
+                List.of(adapter), "a", ref, _ -> 0, BackendQuarantine.none());
+
+        // The pool changes AFTER the composite/launcher is built, and BEFORE the unqualified
+        // worktree spawn — exactly the fleetd #425 scenario: the live pool's first entry is "b" by
+        // the time acquireWithWorktree runs, even though nothing here was rebuilt.
+        Files.writeString(f, worktreeReorderYaml("b", "a"));
+        ConfigRef.Outcome out = ref.reload();
+        assertTrue(out.applied(), () -> "reload should apply cleanly: " + out.error());
+
+        FakeWorktrees worktrees = new FakeWorktrees();
+        SessionManager sessions = new SessionManager(launcher, worktrees, () -> 0L);
+
+        MemberSession s = sessions.acquire(null, null, "/caller",
+                null, new WorktreeRequest("fleetd-425", null));
+
+        assertEquals("b", s.profile(),
+                "the live dev pool now starts at b, so the unqualified spawn must land there");
+        FakeWorktrees.OverlayCall overlay = worktrees.lastOverlay();
+        assertNotNull(overlay, "overlayParity must have been called");
+        assertEquals(List.of("b.mcp.json"), overlay.requested(),
+                "the worktree must be provisioned with profile b's overlay — the one actually "
+                        + "spawned — never a's, the pool's stale first entry");
+    }
+
+    /**
+     * The deterministic, mutation-pinning half of criterion 3: {@code launcher.defaultProfile()}
+     * only ever answers for {@link MemberRole#DEV} (see {@link CompositePeerLauncher#defaultProfile()}),
+     * so resolving a worktree spawn's profile through it — instead of through {@link
+     * PeerLauncher#defaultProfileFor(MemberRole)}, resolved against the CALLER's actual role — picks
+     * the wrong pool's answer for any role other than DEV. No reload or race is needed to see it: an
+     * ARCHITECT pool and a DEV pool that simply disagree, held constant, are enough.
+     */
+    @Test
+    void acquireWithWorktreeForANonDevRoleUsesThatRolesPoolNotTheDevPool() {
+        Map<String, FleetConfig.Profile> profiles = Map.of(
+                "a", new FleetConfig.Profile("a", "http://gx00.gw:8000", "coder-a", null,
+                        "FLEETD_WORKER_TOKEN", List.of("claude"), "tab", "fleetd-workers",
+                        "worker: {profile} #{n}", null, "/repo/a", List.of("a.mcp.json")),
+                "b", new FleetConfig.Profile("b", "http://gx00.gw:8000", "coder-b", null,
+                        "FLEETD_WORKER_TOKEN", List.of("claude"), "tab", "fleetd-workers",
+                        "worker: {profile} #{n}", null, "/repo/b", List.of("b.mcp.json")));
+        FakeHerdr herdr = new FakeHerdr();
+        ClaudeCodeLauncher adapter = new ClaudeCodeLauncher(new AgentControl(herdr), new WorkspaceControl(herdr),
+                new SubscriptionGuard(Set.of("gx00.gw")), profiles, "a", _ -> null);
+        // developers -> a (first/only entry); architects -> b (first/only entry). The two pools
+        // disagree on purpose, so a role-blind resolution (DEV's answer, "a") is visibly wrong for
+        // an ARCHITECT spawn, which must land on "b".
+        FleetConfig.Fleet fleet = new FleetConfig.Fleet(Map.of(),
+                Map.of("s0", new FleetConfig.Slot("b")),
+                Map.of("s0", new FleetConfig.Slot("a")),
+                Map.of(), null);
+        PeerLauncher launcher = new CompositePeerLauncher(List.of(adapter), "a", profiles,
+                PlacementPolicies.fixed(), _ -> 0, fleet);
+
+        FakeWorktrees worktrees = new FakeWorktrees();
+        SessionManager sessions = new SessionManager(launcher, worktrees, () -> 0L);
+
+        MemberSession s = sessions.acquire(null, MemberRole.ARCHITECT, null, "/caller",
+                null, new WorktreeRequest("fleetd-425b", null));
+
+        assertEquals("b", s.profile(),
+                "an unqualified ARCHITECT worktree spawn must land on the architect pool's profile");
+        FakeWorktrees.OverlayCall overlay = worktrees.lastOverlay();
+        assertNotNull(overlay, "overlayParity must have been called");
+        assertEquals(List.of("b.mcp.json"), overlay.requested(),
+                "the worktree must be provisioned with profile b's overlay — the ARCHITECT pool's "
+                        + "answer, the one actually spawned — never a's, the DEV pool's answer that "
+                        + "launcher.defaultProfile() alone would have given");
+    }
 }