fleetd #790: merge PR #792 — an observer pane may fleet_send to a lead

An observer's SEND classifier (CallerResolver.observerSendTarget, renamed from
sendableObserverTarget) now accepts a configured lead terminal as well as
another observer pane. Collaborators, architect slots and spawned members stay
refused. The [fleet_send from observer term_…] prefix is kept. An observer
learns a lead's sessionId from its filtered fleet_list panes rows (role "lead").

Lead verification: mvn clean install on 72ea7de in a throwaway worktree,
exit 0, surefire totals 2208 run / 0 failures / 0 errors / 0 skipped.

Follow-up found in review: #793 (the Injector has no prompt-box gate for a
direct send to a lead pane).

fleetd/src/main/java/dev/ltms/fleet/auth/Authz.java

@@ -80,34 +80,35 @@ public final class Authz {
     /**
      * The fail-closed classifier for an observer's {@code SEND}: answers no for every target, so
      * the grant is refused unless a caller supplies a real one. {@code
-     * CallerResolver#sendableObserverTarget()} is the real one, read from the same maps {@code
-     * CallerResolver#resolve} consults, so a target that classifier calls known is one {@code
-     * resolve} would actually resolve as {@link Role#OBSERVER}.
+     * CallerResolver#observerSendTarget()} is the real one, read from the same maps {@code
+     * CallerResolver#resolve} consults, so a target that classifier accepts is one {@code resolve}
+     * would actually resolve as a lead ({@link Role#PRIMARY}) or as {@link Role#OBSERVER}.
      */
-    public static final Predicate<String> NO_KNOWN_OBSERVER_TARGET = target -> false;
+    public static final Predicate<String> NO_OBSERVER_SEND_TARGET = target -> false;
 
     /**
      * Convenience form for a caller with no classifier to supply. Fails closed: a collaborator's
      * or an observer's {@code SEND} is refused, as if no terminal were a configured lead,
-     * collaborator, or observer target — the same decision {@link #NO_KNOWN_LEAD_OR_COLLABORATOR}
-     * and {@link #NO_KNOWN_OBSERVER_TARGET} give explicitly. Every other action's result is
-     * identical to the five-argument form's, since none of them consult either classifier.
+     * collaborator, or observer-reachable target — the same decision
+     * {@link #NO_KNOWN_LEAD_OR_COLLABORATOR} and {@link #NO_OBSERVER_SEND_TARGET} give explicitly.
+     * Every other action's result is identical to the five-argument form's, since none of them
+     * consult either classifier.
      *
      * <p>Its default classifiers deny every collaborator and every observer, so a caller
      * enforcing authorization must use the five-argument form instead.
      */
     public static boolean permits(Principal caller, Action action, String targetSession) {
-        return permits(caller, action, targetSession, NO_KNOWN_LEAD_OR_COLLABORATOR, NO_KNOWN_OBSERVER_TARGET);
+        return permits(caller, action, targetSession, NO_KNOWN_LEAD_OR_COLLABORATOR, NO_OBSERVER_SEND_TARGET);
     }
 
     /**
      * As {@link #permits(Principal, Action, String)}, with a real classifier for a collaborator's
-     * {@code SEND}. An observer's {@code SEND} still fails closed ({@link #NO_KNOWN_OBSERVER_TARGET}) —
+     * {@code SEND}. An observer's {@code SEND} still fails closed ({@link #NO_OBSERVER_SEND_TARGET}) —
      * a caller enforcing both grants must use the five-argument form.
      */
     public static boolean permits(Principal caller, Action action, String targetSession,
                                    Predicate<String> knownLeadOrCollaborator) {
-        return permits(caller, action, targetSession, knownLeadOrCollaborator, NO_KNOWN_OBSERVER_TARGET);
+        return permits(caller, action, targetSession, knownLeadOrCollaborator, NO_OBSERVER_SEND_TARGET);
     }
 
     /**
@@ -122,14 +123,15 @@ public final class Authz {
      *                                consulted only for a collaborator's {@code SEND}, to confine
      *                                it to another named peer and never a spawned member's
      *                                terminal
-     * @param knownObserverTarget     whether a terminal is one this daemon would itself resolve as
-     *                                {@link Role#OBSERVER} — consulted only for an observer's
-     *                                {@code SEND}, to confine it to another observer pane and never
-     *                                a lead, a collaborator, or a spawned member
+     * @param observerSendTarget      whether a terminal is one this daemon would itself resolve as
+     *                                a lead ({@link Role#PRIMARY}) or as {@link Role#OBSERVER} —
+     *                                consulted only for an observer's {@code SEND}, to confine it
+     *                                to a lead or another observer pane and never a collaborator,
+     *                                an architect, or a spawned member
      */
     public static boolean permits(Principal caller, Action action, String targetSession,
                                    Predicate<String> knownLeadOrCollaborator,
-                                   Predicate<String> knownObserverTarget) {
+                                   Predicate<String> observerSendTarget) {
         if (caller == null || caller.isAnonymous()) {
             return false; // authenticated as nothing ⇒ authorized for nothing
         }
@@ -143,12 +145,12 @@ public final class Authz {
             // Delivering a turn to a local session is open to the primary and the architect
             // unconditionally. A collaborator may reach only a target that is itself a configured
             // lead or collaborator, never a spawned member's terminal. An observer may reach only
-            // a target that would itself resolve as an observer, never a lead, a collaborator, or
-            // a spawned member. A worker is excluded from every case — sending would be it
-            // escalating into the orchestrator role.
+            // a target that would itself resolve as a lead or as another observer, never a
+            // collaborator, an architect, or a spawned member. A worker is excluded from every
+            // case — sending would be it escalating into the orchestrator role.
             case SEND -> caller.isPrimary() || caller.isArchitect()
                     || (caller.isCollaborator() && knownLeadOrCollaborator.test(targetSession))
-                    || (caller.isObserver() && knownObserverTarget.test(targetSession));
+                    || (caller.isObserver() && observerSendTarget.test(targetSession));
 
             // Resolving a worker's blocked question is part of delegating to it, open to the same
             // two roles that may stand up that delegation in the first place. Not a collaborator:

fleetd/src/main/java/dev/ltms/fleet/auth/CallerResolver.java

@@ -271,22 +271,27 @@ public final class CallerResolver {
     }
 
     /**
-     * Whether {@code target} names a terminal this resolver would itself resolve as {@link
-     * Role#OBSERVER} — the classifier an observer's {@code SEND} is checked against, read from the
-     * same maps and functions {@link #resolve} consults so a target this accepts is exactly one
-     * {@code resolve} would hand back {@link Role#OBSERVER} for, and the reverse.
+     * Whether {@code target} names a terminal an observer may {@code SEND} to: one this resolver
+     * would itself resolve as a lead ({@link Role#PRIMARY}) or as {@link Role#OBSERVER}. Read from
+     * the same maps and functions {@link #resolve} consults, and in the same order, so a target
+     * this accepts is exactly one {@code resolve} would hand back one of those two roles for, and
+     * the reverse.
+     *
+     * <p>A live spawned member is refused first, whatever a tab map says about its terminal — the
+     * order {@link #resolve} itself uses. A pane named as a lead is then accepted even when it is
+     * also bound to an architect slot, because that is the role {@code resolve} gives it.
      */
-    public Predicate<String> sendableObserverTarget() {
+    public Predicate<String> observerSendTarget() {
         return target -> target != null
                 && spawnedMemberRole.apply(target) == null
-                && !leadTerminals.get().containsKey(target)
-                && !boundToArchitectSlot(target)
-                && !collaboratorTerminals.get().containsKey(target);
+                && (leadTerminals.get().containsKey(target)
+                        || (!boundToArchitectSlot(target)
+                                && !collaboratorTerminals.get().containsKey(target)));
     }
 
     /**
      * Whether {@code terminal} is bound to a configured slot the live roster still confirms as an
-     * architect — the one classifier {@link #sendableObserverTarget()} and {@code FleetMcp}'s
+     * architect — the one classifier {@link #observerSendTarget()} and {@code FleetMcp}'s
      * {@code panes} row both read, so a pane's reported role and its {@code SEND} reachability can
      * never drift apart.
      */

fleetd/src/main/java/dev/ltms/fleet/auth/Role.java

@@ -52,9 +52,9 @@ public enum Role {
      * like a worker's — derived from the connection's pane, never from a request argument, and
      * honoured regardless of auth mode. May {@code READ} and {@code METRICS}, {@code REPLY}/
      * {@code ASK} only as its own pane, and {@code SEND} only to a target that would itself
-     * resolve as {@code OBSERVER}; may not {@code SPAWN}/{@code STOP}/{@code DRAIN}/
-     * {@code HANDOVER}, poll a ticket ({@code TASK_READ}), or reach the coordination broker
-     * ({@code COORD_SEND}/{@code COORD_READ}).
+     * resolve as a lead ({@link #PRIMARY}) or as {@code OBSERVER}; may not {@code SPAWN}/
+     * {@code STOP}/{@code DRAIN}/{@code HANDOVER}, poll a ticket ({@code TASK_READ}), or reach the
+     * coordination broker ({@code COORD_SEND}/{@code COORD_READ}).
      */
     OBSERVER,
 

fleetd/src/main/java/dev/ltms/fleet/mcp/FleetMcp.java

@@ -121,9 +121,9 @@ public final class FleetMcp {
     /**
      * Kept as a field (rather than only captured by the {@code contextExtractor} closure) so
      * {@link #denyFor} can read {@link CallerResolver#knownLeadOrCollaborator()} and {@link
-     * CallerResolver#sendableObserverTarget()} — the classifiers a collaborator's and an
-     * observer's {@code SEND} are each checked against, built from the same maps {@link #identity}-
-     * based resolution reads.
+     * CallerResolver#observerSendTarget()} — the classifiers a collaborator's and an observer's
+     * {@code SEND} are each checked against, built from the same maps {@link #identity}-based
+     * resolution reads.
      */
     private final CallerResolver callers;
     private final Metrics metrics;      // CB-502: null → auth failures not counted
@@ -323,12 +323,12 @@ public final class FleetMcp {
      *                     injector, keyed by terminal id — never a second, separately-derived check
      * @param architectSlot the same classifier {@link CallerResolver#boundToArchitectSlot} resolves
      *                     a caller against — never a second, separately-derived check
-     * @param sendableToObserver the same predicate {@link CallerResolver#sendableObserverTarget}
+     * @param observerSendTarget the same predicate {@link CallerResolver#observerSendTarget}
      *                     builds for the {@code SEND} gate — never a second, separately-derived
      *                     check
      */
     public record PaneSource(Supplier<Map<String, String>> tabLabels, Supplier<Map<String, String>> workspaceLabels,
-            Predicate<String> deliverable, Predicate<String> architectSlot, Predicate<String> sendableToObserver) {
+            Predicate<String> deliverable, Predicate<String> architectSlot, Predicate<String> observerSendTarget) {
         /** Inert source — no labels, no deliverable targets, no architect slots, nothing sendable. */
         public static PaneSource none() {
             return new PaneSource(Map::of, Map::of, _ -> false, _ -> false, _ -> false);
@@ -616,7 +616,7 @@ public final class FleetMcp {
                     PaneSource panes = new PaneSource(() -> identity.panes().tabLabelsByTabId(),
                             () -> identity.panes().workspaceLabelsByWorkspaceId(),
                             Fleetd.deliverableTo(presence, callers::leads, callers::collaborators),
-                            callers::boundToArchitectSlot, callers.sendableObserverTarget());
+                            callers::boundToArchitectSlot, callers.observerSendTarget());
                     return listFleet(workers, sessions, messages, capacity, healthCoverage, loopHealth, quarantine, outage,
                             leadSeats, leadContextGauge, leadConfigDirs, callers.leads(),
                             callerTerminal(exchange),
@@ -764,7 +764,7 @@ public final class FleetMcp {
             return null; // AuthorizationMode.UNENFORCED: authorization not enforced (fleetd #518)
         }
         if (Authz.permits(caller, action, target, callers.knownLeadOrCollaborator(),
-                callers.sendableObserverTarget())) {
+                callers.observerSendTarget())) {
             if (action != Authz.Action.READ && action != Authz.Action.TASK_READ) {
                 AuditLog.allowed(caller, action, target); // reads would drown the trail
             }
@@ -826,13 +826,15 @@ public final class FleetMcp {
     }
 
     /**
-     * Who may see {@code fleet_list}'s {@code leads} array — exactly the roles that may
-     * {@link Authz.Action#SEND} to a lead: the primary, an architect, and a collaborator. A
-     * collaborator's own {@code fleet_whoami} carries no lead address, and {@code leads} is the
-     * only place this tool gives one, so a collaborator needs this array to use the send it
-     * already holds. A worker can never {@code SEND} at all, so it still sees neither this array
-     * nor {@code members}; a worker's own facts come from {@code fleet_whoami} instead. Split
-     * out for the same reason as {@link #coordinatorVisibleTo} and
+     * Who may see {@code fleet_list}'s {@code leads} array — the primary, an architect, and a
+     * collaborator. A collaborator's own {@code fleet_whoami} carries no lead address, and this is
+     * the only place this tool gives one, so a collaborator needs this array to use the
+     * {@link Authz.Action#SEND} it already holds. An observer holds that send to a lead too, but
+     * learns the address from its filtered {@code panes} rows instead: a {@code leads} row carries
+     * a lead's name, its configured context window and its config dir, which are the fleet's own
+     * shape rather than an address. A worker can never {@code SEND} at all, so it still sees
+     * neither this array nor {@code members}; a worker's own facts come from {@code fleet_whoami}
+     * instead. Split out for the same reason as {@link #coordinatorVisibleTo} and
      * {@link #collaboratorsVisibleTo}: the decision must be unit-testable without fabricating an
      * SDK {@code McpSyncServerExchange}, and the handler must call this named predicate rather
      * than inlining the check.
@@ -855,9 +857,10 @@ public final class FleetMcp {
     /**
      * Who may see {@code fleet_list}'s {@code panes} array — every role that may
      * {@link Authz.Action#SEND} to some other pane. A plain worker holds {@code READ} but never
-     * {@code SEND}, so it still does not see this array. An observer does hold {@code SEND}, to
-     * another observer pane only, so it sees the array too — but {@code listFleet} filters its rows
-     * to {@link CallerResolver#sendableObserverTarget} and reduces each one; see {@code paneRows}.
+     * {@code SEND}, so it still does not see this array. An observer does hold {@code SEND}, to a
+     * lead or another observer pane, so it sees the array too — and it is the only place this tool
+     * gives it a lead's address. {@code listFleet} filters its rows to
+     * {@link CallerResolver#observerSendTarget} and reduces each one; see {@code paneRows}.
      */
     static boolean panesVisibleTo(Principal caller) {
         return caller.isPrimary() || caller.isArchitect() || caller.isCollaborator() || caller.isObserver();
@@ -2155,8 +2158,8 @@ public final class FleetMcp {
     }
 
     /**
-     * As above, plus fleetd #758: an observer sees the {@code panes} array too, but filtered to
-     * {@link CallerResolver#sendableObserverTarget} and each row reduced to the five fields an
+     * As above, plus: an observer sees the {@code panes} array too, but filtered to
+     * {@link CallerResolver#observerSendTarget} and each row reduced to the five fields an
      * observer may learn — see {@code paneRows}/{@code paneRow}.
      *
      * @param callerIsObserver whether the {@code fleet_list} caller is an observer; every wrapper
@@ -2579,9 +2582,10 @@ public final class FleetMcp {
      * already read, so a pane neither configured as a lead nor spawned as a member — a hand-opened
      * tab — still gets a row here.
      *
-     * <p>fleetd #758: for an observer caller ({@code observerView}), the rows are filtered to
-     * {@link PaneSource#sendableToObserver} before being built, and each row is reduced — see
-     * {@code paneRow}.
+     * <p>For an observer caller ({@code observerView}), the rows are filtered to
+     * {@link PaneSource#observerSendTarget} before being built, and each row is reduced — see
+     * {@code paneRow}. A lead's pane survives that filter, so it is where an observer reads a
+     * lead's {@code sessionId}.
      */
     private static List<Map<String, Object>> paneRows(Map<String, Agent> live, List<MemberSession> roster,
             Map<String, String> leads, Map<String, String> collaborators, PaneSource panes,
@@ -2592,7 +2596,7 @@ public final class FleetMcp {
                 .filter(s -> s.terminalId() != null)
                 .collect(Collectors.toMap(MemberSession::terminalId, Function.identity(), (_, b) -> b));
         return live.values().stream()
-                .filter(a -> !observerView || panes.sendableToObserver().test(a.terminalId()))
+                .filter(a -> !observerView || panes.observerSendTarget().test(a.terminalId()))
                 .sorted(Comparator.comparing(Agent::terminalId))
                 .map(a -> paneRow(a, byTerminal.get(a.terminalId()), leads, collaborators, tabLabels,
                         workspaceLabels, panes, observerView))
@@ -2607,9 +2611,9 @@ public final class FleetMcp {
      * @param workspaceLabels workspace id → its herdr display label (the space name); a workspace
      *                   absent here, or carrying a {@code null} label itself, projects as a
      *                   {@code null} "workspaceLabel"
-     * @param observerView fleetd #758: an observer's row carries only {@code sessionId}, {@code
-     *                   label}, {@code status}, {@code role}, {@code deliverable} — never {@code
-     *                   paneId} (the {@code fleet_stop} handle), {@code workspaceId},
+     * @param observerView an observer's row carries only {@code sessionId}, {@code label},
+     *                   {@code status}, {@code role}, {@code deliverable} — never {@code paneId}
+     *                   (the {@code fleet_stop} handle), {@code workspaceId},
      *                   {@code workspaceLabel}, {@code tabId}, {@code agentType}, or {@code cwd}
      *                   (a member's worktree path is the lead's business)
      */
@@ -2857,9 +2861,12 @@ public final class FleetMcp {
         return tool(FleetTool.LIST.wireName(),
                 "List the whole fleet the bridge tracks, in two parts. 'members' is visible to "
                         + "the primary and an architect only. 'leads' is visible to those two AND a "
-                        + "collaborator — exactly the roles that may fleet_send to a lead, so a "
-                        + "collaborator can learn a lead's sessionId before using the send it already "
-                        + "holds. A worker holds READ to call this tool at all, but gets neither "
+                        + "collaborator, so a collaborator can learn a lead's sessionId before using "
+                        + "the send it already holds. An observer may fleet_send to a lead too, but "
+                        + "reads that sessionId from its own 'panes' rows instead: a 'panes' row for "
+                        + "an observer is filtered to the panes it may send to — a lead's pane and "
+                        + "another observer's — and reduced to sessionId, label, status, role and "
+                        + "deliverable. A worker holds READ to call this tool at all, but gets neither "
                         + "array, never an empty one; a worker reads its own session, "
                         + "profile, state, worktree, branch and owner from fleet_whoami instead. "
                         + "'leads' are your PEERS — other "

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

@@ -285,13 +285,12 @@ public final class FleetApp {
     /**
      * As {@link #permitsFor(Principal, Authz.Action, String, Predicate)}, also threading the
      * classifier an observer's {@code SEND} is checked against; pass {@link #auth}'s own
-     * {@code sendableObserverTarget()} to exercise the real production gate, as {@link #allow}
-     * does.
+     * {@code observerSendTarget()} to exercise the real production gate, as {@link #allow} does.
      */
     static boolean permitsFor(Principal caller, Authz.Action action, String target,
                               Predicate<String> knownLeadOrCollaborator,
-                              Predicate<String> knownObserverTarget) {
-        return Authz.permits(caller, action, target, knownLeadOrCollaborator, knownObserverTarget);
+                              Predicate<String> observerSendTarget) {
+        return Authz.permits(caller, action, target, knownLeadOrCollaborator, observerSendTarget);
     }
 
     /**
@@ -307,7 +306,7 @@ public final class FleetApp {
             return true; // legacy: authorization not enforced
         }
         Principal caller = ctx.attribute(CALLER);
-        if (permitsFor(caller, action, target, auth.knownLeadOrCollaborator(), auth.sendableObserverTarget())) {
+        if (permitsFor(caller, action, target, auth.knownLeadOrCollaborator(), auth.observerSendTarget())) {
             if (action != Authz.Action.READ && action != Authz.Action.METRICS
                     && action != Authz.Action.TASK_READ) {
                 AuditLog.allowed(caller, action, target); // reads would drown the trail

fleetd/src/test/java/dev/ltms/fleet/auth/CallerResolverTest.java

@@ -912,42 +912,65 @@ class CallerResolverTest {
         assertFalse(r.knownLeadOrCollaborator().test("term_a"));
     }
 
-    // ── fleetd #743: sendableObserverTarget() reads the same maps and functions resolve() does ────
+    // ── observerSendTarget() reads the same maps and functions resolve() does, in the same order ──
 
     /**
      * A terminal this resolver recognises as none of the privileged roles is exactly the one
      * {@code resolve} would itself hand back {@link Role#OBSERVER} for.
      */
     @Test
-    void sendableObserverTargetIsTrueForATerminalKnownAsNoOtherRole() {
+    void observerSendTargetIsTrueForATerminalKnownAsNoOtherRole() {
         CallerResolver r = CallerResolver.withLeadsAndMembers(workerIdentity(), false, null,
                 () -> Map.of("term_lead", "opus-5.0"), new MemberRegistry(null),
                 t -> "term_worker".equals(t) ? MemberRole.DEV : null,
                 () -> Map.of("term_collab", "ops"));
 
-        assertTrue(r.sendableObserverTarget().test("term_other"));
+        assertTrue(r.observerSendTarget().test("term_other"));
     }
 
+    /**
+     * A configured lead's own terminal is reachable: an observer may open a conversation with a
+     * lead, and this is the classifier that grant is checked against.
+     */
     @Test
-    void sendableObserverTargetIsFalseForALeadTerminal() {
+    void observerSendTargetIsTrueForALeadTerminal() {
         CallerResolver r = CallerResolver.withLeadsAndMembers(workerIdentity(), false, null,
                 () -> Map.of("term_lead", "opus-5.0"), new MemberRegistry(null), t -> null, Map::of);
 
-        assertFalse(r.sendableObserverTarget().test("term_lead"),
-                "a lead's own terminal must never be a sendable observer target");
+        assertTrue(r.observerSendTarget().test("term_lead"),
+                "a lead's own terminal must be reachable from an observer pane");
+    }
+
+    /**
+     * A pane named as a lead AND bound to an architect slot resolves as the lead, because
+     * {@code resolve} reads the lead map first — so the classifier must accept it, or a pane's
+     * resolved role and its reachability would disagree.
+     */
+    @Test
+    void observerSendTargetIsTrueForALeadTerminalThatIsAlsoABoundArchitectSlot() {
+        CallerResolver r = CallerResolver.withLeadsAndMembers(workerIdentity(), false, null,
+                () -> Map.of("term_a", "opus-5.0"),
+                boundMembers("architect:lead-designer", MemberRole.ARCHITECT), t -> null, Map::of);
+
+        assertEquals(Role.PRIMARY, r.resolve("127.0.0.1", 42, null).role(),
+                "premise: the lead map is read before the architect registry");
+        assertTrue(r.observerSendTarget().test("term_a"));
     }
 
     @Test
-    void sendableObserverTargetIsFalseForACollaboratorTerminal() {
-        CallerResolver r = CallerResolver.withLeadsAndMembers(workerIdentity(), false, null, Map::of,
+    void observerSendTargetIsFalseForACollaboratorTerminal() {
+        CallerResolver r = CallerResolver.withLeadsAndMembers(workerIdentity(), false, null,
+                () -> Map.of("term_lead", "opus-5.0"),
                 new MemberRegistry(null), t -> null, () -> Map.of("term_collab", "ops"));
 
-        assertFalse(r.sendableObserverTarget().test("term_collab"),
-                "a collaborator's own terminal must never be a sendable observer target");
+        assertFalse(r.observerSendTarget().test("term_collab"),
+                "a collaborator's own terminal must never be reachable from an observer pane");
+        // CONTROL: the same wiring, a target recognised as no configured role at all.
+        assertTrue(r.observerSendTarget().test("term_other"));
     }
 
     @Test
-    void sendableObserverTargetIsFalseForALiveSpawnedMembersTerminal() {
+    void observerSendTargetIsFalseForALiveSpawnedMembersTerminal() {
         // Covers both a worker and an architect: spawnedMemberRole.apply(target) is non-null for
         // either, and resolve() never falls through to OBSERVER once it is.
         CallerResolver r = CallerResolver.withLeadsAndMembers(workerIdentity(), false, null, Map::of,
@@ -958,26 +981,47 @@ class CallerResolverTest {
                     default -> null;
                 }, Map::of);
 
-        assertFalse(r.sendableObserverTarget().test("term_worker"));
-        assertFalse(r.sendableObserverTarget().test("term_architect"));
+        assertFalse(r.observerSendTarget().test("term_worker"));
+        assertFalse(r.observerSendTarget().test("term_architect"));
+        // CONTROL: the same wiring, a target the member lookup above answers null for.
+        assertTrue(r.observerSendTarget().test("term_other"));
+    }
+
+    /**
+     * A lead map entry does not rescue a terminal a live spawned member occupies: the member
+     * lookup runs first, exactly as in {@code resolve}.
+     */
+    @Test
+    void observerSendTargetIsFalseForASpawnedMemberOnATerminalTheLeadMapAlsoNames() {
+        CallerResolver r = CallerResolver.withLeadsAndMembers(workerIdentity(), false, null,
+                () -> Map.of("term_worker", "opus-5.0"), new MemberRegistry(null),
+                t -> "term_worker".equals(t) ? MemberRole.DEV : null, Map::of);
+
+        assertFalse(r.observerSendTarget().test("term_worker"));
+        // CONTROL: the same wiring, the same lead map, a terminal no member occupies.
+        assertTrue(r.observerSendTarget().test("term_other"));
     }
 
     @Test
-    void sendableObserverTargetIsFalseForABoundArchitectSlotWithNoLiveMember() {
+    void observerSendTargetIsFalseForABoundArchitectSlotWithNoLiveMember() {
         // The edge case resolve() itself carries: a terminal bound to a configured architect slot
         // but with no live spawned-member session yet.
         CallerResolver r = CallerResolver.withLeadsAndMembers(workerIdentity(), false, null, Map::of,
                 boundMembers("architect:lead-designer", MemberRole.ARCHITECT), t -> null, Map::of);
 
-        assertFalse(r.sendableObserverTarget().test("term_a"));
+        assertFalse(r.observerSendTarget().test("term_a"));
+        // CONTROL: the same wiring, a terminal the bind above never touched.
+        assertTrue(r.observerSendTarget().test("term_other"));
     }
 
     @Test
-    void sendableObserverTargetIsFalseForANullTarget() {
+    void observerSendTargetIsFalseForANullTarget() {
         CallerResolver r = CallerResolver.withLeadsAndMembers(workerIdentity(), false, null, Map::of,
                 new MemberRegistry(null), t -> null, Map::of);
 
-        assertFalse(r.sendableObserverTarget().test(null));
+        assertFalse(r.observerSendTarget().test(null));
+        // CONTROL: the same wiring, a non-null target.
+        assertTrue(r.observerSendTarget().test("term_other"));
     }
 
 }

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

@@ -270,18 +270,19 @@ class FleetMcpAuthzTest {
                 "a spawned member's own terminal must stay unreachable, even once the classifier is real");
     }
 
-    // --- fleetd #743: the observer SEND matrix, over MCP's denyFor -------------------------------
+    // --- the observer SEND matrix, over MCP's denyFor -------------------------------------------
 
     private static final Principal OBSERVER = Principal.observer("term_observer", 700);
 
     /**
      * Wires one real {@link CallerResolver} that recognises a lead, a collaborator, and a live
      * spawned worker, leaving "term_other_observer" classified as none of them — so the same
-     * wiring both denies an observer's {@code SEND} to every privileged role and grants it to
-     * another unclassified pane, proving the refusals are the rule and not a missing fixture.
+     * wiring denies an observer's {@code SEND} to a collaborator and to a member while granting
+     * it to a lead and to another unclassified pane, proving the refusals are the rule and not a
+     * missing fixture.
      */
     @Test
-    void anObserverMaySendOnlyToAnotherObserverNeverToALeadWorkerOrArchitect() {
+    void anObserverMaySendToALeadOrAnotherObserverButNeverToACollaboratorOrAMember() {
         ConnectionIdentity identity = new ConnectionIdentity(new PaneLocator(herdr), _ -> 999_999);
         CallerResolver callers = CallerResolver.withLeadsAndMembers(identity, false, null,
                 () -> Map.of("term_lead_known", "lead-x"), new MemberRegistry(null),
@@ -289,22 +290,23 @@ class FleetMcpAuthzTest {
                 () -> Map.of("term_collab_known", "ops2"));
         FleetMcp m = mcp(true, callers);
 
-        assertNotNull(m.denyFor(OBSERVER, Authz.Action.SEND, "term_lead_known"),
-                "an observer must never reach a lead's terminal");
+        assertNull(m.denyFor(OBSERVER, Authz.Action.SEND, "term_lead_known"),
+                "an observer must reach a lead's terminal, so a peer session can open a "
+                        + "conversation with a lead");
         assertNotNull(m.denyFor(OBSERVER, Authz.Action.SEND, "term_collab_known"),
                 "an observer must never reach a collaborator's terminal");
         assertNotNull(m.denyFor(OBSERVER, Authz.Action.SEND, "term_a"),
                 "an observer must never reach a live spawned member's terminal");
 
         // CONTROL: the same wiring, the same denyFor call, a target recognised as none of the
-        // three privileged roles above -- this is what proves the three refusals above are the
-        // rule working, not a classifier that refuses every target regardless of what it is.
+        // configured roles above -- this is what proves the two refusals above are the rule
+        // working, not a classifier that refuses every target regardless of what it is.
         assertNull(m.denyFor(OBSERVER, Authz.Action.SEND, "term_other_observer"),
                 "an observer must reach another pane that resolves as an observer itself");
     }
 
     /**
-     * As {@link #anObserverMaySendOnlyToAnotherObserverNeverToALeadWorkerOrArchitect}, for a
+     * As {@link #anObserverMaySendToALeadOrAnotherObserverButNeverToACollaboratorOrAMember}, for a
      * terminal bound to a configured architect slot but hosting no live spawned-member session --
      * the case {@link CallerResolver#resolve} itself treats separately from a live worker/architect.
      */
@@ -324,6 +326,26 @@ class FleetMcpAuthzTest {
         assertNull(m.denyFor(OBSERVER, Authz.Action.SEND, "term_other_observer"));
     }
 
+    /**
+     * An observer's reach is widened for {@code SEND} alone. It still holds no {@code TASK_READ},
+     * so it cannot poll a ticket or read a lead's session status, and no {@code SPAWN}/
+     * {@code STOP}/{@code COORD_SEND}, so it cannot drive the fleet it can now message.
+     */
+    @Test
+    void anObserverReachingALeadStillHoldsNoTicketReadAndNoLifecycle() {
+        ConnectionIdentity identity = new ConnectionIdentity(new PaneLocator(herdr), _ -> 999_999);
+        CallerResolver callers = CallerResolver.withLeadsAndMembers(identity, false, null,
+                () -> Map.of("term_lead_known", "lead-x"), new MemberRegistry(null), t -> null, Map::of);
+        FleetMcp m = mcp(true, callers);
+
+        assertNull(m.denyFor(OBSERVER, Authz.Action.SEND, "term_lead_known"),
+                "premise: this wiring grants the observer's send to that lead");
+        assertNotNull(m.denyFor(OBSERVER, Authz.Action.TASK_READ, "term_lead_known"));
+        assertNotNull(m.denyFor(OBSERVER, Authz.Action.SPAWN, null));
+        assertNotNull(m.denyFor(OBSERVER, Authz.Action.STOP, null));
+        assertNotNull(m.denyFor(OBSERVER, Authz.Action.COORD_SEND, null));
+    }
+
     @Test
     void theLegacyConstructorLeavesTheGateOpen() {
         // The 22 pre-existing FleetMcpTest cases rely on no authorization being enforced.
@@ -477,9 +499,10 @@ class FleetMcpAuthzTest {
 
     /**
      * {@link FleetMcp#leadsVisibleTo} is the whole policy decision for {@code fleet_list}'s
-     * {@code leads} array: visible to exactly the roles that may {@code SEND} to a lead -- the
-     * primary, an architect, and a collaborator -- never a worker, which holds {@code READ} but
-     * can never {@code SEND} at all, and never an anonymous caller.
+     * {@code leads} array: visible to the primary, an architect, and a collaborator -- never a
+     * worker, which holds {@code READ} but can never {@code SEND} at all, never an observer, which
+     * reads a lead's address from its filtered {@code panes} rows instead, and never an anonymous
+     * caller.
      */
     @Test
     void primaryArchitectAndCollaboratorMaySeeTheLeadsArray() {
@@ -489,6 +512,9 @@ class FleetMcpAuthzTest {
                 "a collaborator may SEND to a lead, so it must see the leads array to learn where");
         assertFalse(FleetMcp.leadsVisibleTo(WORKER_A),
                 "a worker holds READ but can never SEND, so it must not see the leads array");
+        assertFalse(FleetMcp.leadsVisibleTo(Principal.observer("term_obs", 700)),
+                "an observer may SEND to a lead but learns the address from its panes rows, which "
+                        + "carry no lead name, context window or config dir");
         assertFalse(FleetMcp.leadsVisibleTo(ANON), "authenticated as nothing must not see it either");
     }
 
@@ -513,8 +539,8 @@ class FleetMcpAuthzTest {
     /**
      * {@link FleetMcp#panesVisibleTo} is the whole policy decision for {@code fleet_list}'s
      * {@code panes} array: visible to every role that may {@code SEND} to some other pane -- the
-     * primary, an architect, a collaborator, and an observer (to another observer pane only, with
-     * its row filtered and reduced -- see {@code listFleet}) -- never a worker, never an
+     * primary, an architect, a collaborator, and an observer (to a lead or another observer pane,
+     * with its rows filtered and reduced -- see {@code listFleet}) -- never a worker, never an
      * anonymous caller.
      */
     @Test
@@ -525,8 +551,8 @@ class FleetMcpAuthzTest {
         assertFalse(FleetMcp.panesVisibleTo(WORKER_A),
                 "a worker holds READ but can never SEND, so it must not see the panes array");
         assertTrue(FleetMcp.panesVisibleTo(Principal.observer("term_obs", 700)),
-                "an observer holds SEND to another observer pane, so it must see the (filtered, "
-                        + "reduced) panes array");
+                "an observer holds SEND to a lead and to another observer pane, so it must see the "
+                        + "(filtered, reduced) panes array");
         assertFalse(FleetMcp.panesVisibleTo(ANON), "authenticated as nothing must not see it either");
     }
 

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

@@ -0,0 +1,178 @@
+package dev.ltms.fleet.mcp;
+
+import dev.ltms.fleet.Fleetd;
+import dev.ltms.fleet.auth.CallerResolver;
+import dev.ltms.fleet.auth.MemberRegistry;
+import dev.ltms.fleet.config.FleetConfig;
+import dev.ltms.fleet.guard.SubscriptionGuard;
+import dev.ltms.fleet.herdr.AgentControl;
+import dev.ltms.fleet.herdr.AgentStatus;
+import dev.ltms.fleet.herdr.FakeHerdr;
+import dev.ltms.fleet.herdr.PaneLocator;
+import dev.ltms.fleet.herdr.WorkspaceControl;
+import dev.ltms.fleet.inject.Injector;
+import dev.ltms.fleet.inject.MemberPresence;
+import dev.ltms.fleet.inject.TurnListener;
+import dev.ltms.fleet.member.ClaudeCodeLauncher;
+import dev.ltms.fleet.msg.InMemoryReplyInbox;
+import dev.ltms.fleet.msg.MessageService;
+import dev.ltms.fleet.msg.Rendezvous;
+import dev.ltms.fleet.session.FakeWorktrees;
+import dev.ltms.fleet.session.SessionManager;
+import io.modelcontextprotocol.client.McpClient;
+import io.modelcontextprotocol.client.McpSyncClient;
+import io.modelcontextprotocol.client.transport.HttpClientStreamableHttpTransport;
+import io.modelcontextprotocol.spec.McpClientTransport;
+import io.modelcontextprotocol.spec.McpSchema;
+import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.server.ServerConnector;
+import org.eclipse.jetty.servlet.ServletContextHandler;
+import org.eclipse.jetty.servlet.ServletHolder;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.Predicate;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * An observer's {@code fleet_send} to a lead, driven end to end: a real MCP client over a real
+ * HTTP transport, resolved by the real {@link CallerResolver} to
+ * {@link dev.ltms.fleet.auth.Role#OBSERVER}, through the real {@link MessageService} and the real
+ * {@link Injector} to the point of its real herdr call.
+ *
+ * <p>{@link FleetMcpAuthzTest} proves {@code denyFor} grants this case. This is the path that also
+ * proves the grant is not dead at the injector's readiness gate: that gate is the production
+ * {@link Fleetd#deliverableTo} predicate, and the lead's terminal carries no
+ * {@link MemberPresence} entry, so the delivery can only pass by the lead being a configured lead.
+ */
+class FleetMcpObserverSendToLeadDeliveryTest {
+
+    private static final String LEAD = "term_lead_pane";
+    private static final String COLLABORATOR = "term_collab_pane";
+
+    private final FakeHerdr herdr = new FakeHerdr();
+    private final AgentControl agents = new AgentControl(herdr);
+    private final Rendezvous rendezvous = new Rendezvous();
+    private final MemberPresence presence = new MemberPresence();
+    private Injector injector;
+    private MessageService messages;
+    private FleetMcp mcp;
+    private Server server;
+    private String baseUrl;
+
+    @BeforeEach
+    void startServer() throws Exception {
+        FleetConfig.Profile cfg = new FleetConfig.Profile(
+                "ltms-local", "http://gx00.gw:8000", "coder", null, "FLEETD_WORKER_TOKEN", null,
+                "tab", "fleetd-workers", "worker: {profile} #{n}", null, null, null);
+        ClaudeCodeLauncher workers = new ClaudeCodeLauncher(agents, new WorkspaceControl(herdr),
+                new SubscriptionGuard(Set.of("gx00.gw")), Map.of(cfg.profile(), cfg), cfg.profile(),
+                _ -> "tok");
+        SessionManager sessions = new SessionManager(workers, new FakeWorktrees());
+        // The fake's pane list carries a second pane, "term_shell", whose shell pid is 9001 and
+        // which hosts no agent -- so the real resolver lands the caller on the observer floor.
+        ConnectionIdentity identity = new ConnectionIdentity(new PaneLocator(herdr), _ -> 9001L);
+        CallerResolver callers = CallerResolver.withLeadsAndMembers(identity, false, null,
+                () -> Map.of(LEAD, "fleet01-lead"), new MemberRegistry(null),
+                _ -> null, () -> Map.of(COLLABORATOR, "ops"));
+
+        Predicate<String> deliverable =
+                Fleetd.deliverableTo(presence, callers::leads, callers::collaborators);
+        injector = new Injector(agents, TurnListener.NOOP, deliverable);
+        messages = new MessageService(agents, injector, rendezvous, new InMemoryReplyInbox());
+
+        mcp = new FleetMcp(messages, workers, sessions, identity, presence,
+                new PrimaryRegistry(null), callers, FleetMcp.AuthorizationMode.ENFORCED,
+                null, FleetMcp.CapacitySource.none(), new FleetMcp.HealthCoverageSource(() -> "off"),
+                FleetMcp.QuarantineSource.none(), null, FleetMcp.OutageSource.none(),
+                FleetMcp.LeadSeatSource.none(), List.of(), null);
+
+        ServletContextHandler handler = new ServletContextHandler();
+        handler.setContextPath("/");
+        handler.addServlet(new ServletHolder(mcp.servlet()), "/mcp");
+        server = new Server(0);
+        server.setHandler(handler);
+        server.start();
+        baseUrl = "http://127.0.0.1:"
+                + ((ServerConnector) server.getConnectors()[0]).getLocalPort();
+    }
+
+    @AfterEach
+    void tearDown() throws Exception {
+        if (server != null) {
+            server.stop();
+        }
+        if (mcp != null) {
+            mcp.close();
+        }
+    }
+
+    @Test
+    void anObserversSendToALeadIsAttributedAndReachesTheRealInjector() throws Exception {
+        assertFalse(presence.isPresent(LEAD),
+                "premise: the lead's terminal is deliverable only as a configured lead, never "
+                        + "through a presence entry");
+
+        McpSchema.CallToolResult result = sendFleetSend(LEAD, "can we split the review?");
+        assertFalse(result.isError(), "an observer sending to a lead must be accepted: "
+                + textOf(result));
+
+        long waiterDeadline = System.currentTimeMillis() + 3000;
+        while (!rendezvous.isWaiting(LEAD) && System.currentTimeMillis() < waiterDeadline) {
+            Thread.sleep(5);
+        }
+        assertTrue(rendezvous.isWaiting(LEAD), "the async send must have opened its rendezvous waiter");
+
+        injector.onStatus(LEAD, AgentStatus.IDLE); // drives the real delivery attempt to herdr
+
+        long deliveryDeadline = System.currentTimeMillis() + 3000;
+        while (!herdr.called("agent.prompt") && System.currentTimeMillis() < deliveryDeadline) {
+            Thread.sleep(5);
+        }
+        assertTrue(herdr.called("agent.prompt"), "the delivery attempt must have reached herdr");
+
+        @SuppressWarnings("unchecked")
+        Map<String, Object> params = (Map<String, Object>) herdr.lastCall("agent.prompt").params();
+        assertEquals("[fleet_send from observer term_shell]\ncan we split the review?",
+                params.get("text"),
+                "a lead must see the sender's own daemon-resolved terminal, never a raw echo of "
+                        + "the content and never a client-supplied name");
+    }
+
+    /**
+     * Control for the test above, over the same live server and the same wiring: the grant is
+     * specific to a lead target, so a collaborator's terminal is still refused at the handler and
+     * nothing is ever queued for it.
+     */
+    @Test
+    void thatSameObserverIsStillRefusedACollaboratorsTerminal() {
+        McpSchema.CallToolResult result = sendFleetSend(COLLABORATOR, "can we split the review?");
+
+        assertTrue(result.isError(), "an observer must not reach a collaborator's terminal");
+        assertFalse(rendezvous.isWaiting(COLLABORATOR),
+                "a refused send must never open a waiter for its target");
+    }
+
+    private McpSchema.CallToolResult sendFleetSend(String target, String content) {
+        McpClientTransport transport = HttpClientStreamableHttpTransport.builder(baseUrl)
+                .endpoint("/mcp")
+                .build();
+        try (McpSyncClient client = McpClient.sync(transport).build()) {
+            client.initialize();
+            return client.callTool(McpSchema.CallToolRequest.builder("fleet_send")
+                    .arguments(Map.of("sessionId", target, "content", content, "wait", false))
+                    .build());
+        }
+    }
+
+    private static String textOf(McpSchema.CallToolResult r) {
+        return ((McpSchema.TextContent) r.content().getFirst()).text();
+    }
+}

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

@@ -1239,7 +1239,7 @@ class FleetMcpTest {
     /**
      * fleetd #756: a pane bound to a configured architect slot with no live member session must
      * report {@code role: "architect"}, read from {@link CallerResolver#boundToArchitectSlot} —
-     * the same classifier {@link CallerResolver#sendableObserverTarget} refuses as a {@code SEND}
+     * the same classifier {@link CallerResolver#observerSendTarget} refuses as a {@code SEND}
      * target — rather than falling through to {@code "observer"}.
      */
     @Test
@@ -1276,14 +1276,13 @@ class FleetMcpTest {
     }
 
     /**
-     * fleetd #758: an observer's {@code fleet_list} now carries a {@code panes} key, filtered to
-     * {@link CallerResolver#sendableObserverTarget} (so a lead's pane, a spawned member's pane, a
-     * collaborator's pane, and an unoccupied architect-slot pane are all absent) and every
-     * surviving row reduced to exactly {@code sessionId}, {@code label}, {@code status},
+     * An observer's {@code fleet_list} carries a {@code panes} key, filtered to
+     * {@link CallerResolver#observerSendTarget} (so a lead's pane survives, while a spawned
+     * member's pane, a collaborator's pane and an unoccupied architect-slot pane are all absent)
+     * and every surviving row reduced to exactly {@code sessionId}, {@code label}, {@code status},
      * {@code role}, {@code deliverable} — never {@code paneId}, {@code workspaceId},
-     * {@code workspaceLabel} (fleetd #771 — a space name is host shape, a stronger disclosure than
-     * a pane id, so it stays out of the reduced row too), {@code tabId}, {@code agentType}, or
-     * {@code cwd}.
+     * {@code workspaceLabel} (a space name is host shape, a stronger disclosure than a pane id, so
+     * it stays out of the reduced row too), {@code tabId}, {@code agentType}, or {@code cwd}.
      */
     @Test
     void listFiltersAndReducesThePanesArrayForAnObserver() {
@@ -1306,7 +1305,7 @@ class FleetMcpTest {
         FleetMcp.PaneSource panes = new FleetMcp.PaneSource(
                 () -> new PaneLocator(h).tabLabelsByTabId(),
                 () -> new PaneLocator(h).workspaceLabelsByWorkspaceId(), _ -> true,
-                callers::boundToArchitectSlot, callers.sendableObserverTarget());
+                callers::boundToArchitectSlot, callers.observerSendTarget());
 
         String out = textOf(listFleetAsObserver(h, callers.leads(),
                 Map.of("term_collab_pane", "ops"), panes));
@@ -1314,7 +1313,10 @@ class FleetMcpTest {
         assertTrue(out.contains("\"panes\":["), out);
         assertTrue(out.contains("\"sessionId\":\"term_sendable\""),
                 "an ordinary unclassified pane must still be sendable and visible: " + out);
-        assertFalse(out.contains("term_lead_pane"), "a lead's pane must not be enumerated: " + out);
+        assertTrue(out.contains("\"sessionId\":\"term_lead_pane\""),
+                "a lead's pane is where an observer reads the sessionId its send needs: " + out);
+        assertTrue(out.contains("\"role\":\"lead\""),
+                "the lead's row must name the role, so an observer can tell it from a peer pane: " + out);
         assertFalse(out.contains("term_member_pane"), "a spawned member's pane must not be enumerated: " + out);
         assertFalse(out.contains("term_collab_pane"), "a collaborator's pane must not be enumerated: " + out);
         assertFalse(out.contains("term_architect_pane"),

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

@@ -694,6 +694,27 @@ class FleetAppAuthTest {
         assertEquals(403, toSpawnedMembersTerminal.statusCode(), toSpawnedMembersTerminal.body());
     }
 
+    /**
+     * The REST route must give the same answer as MCP for an observer: pid 9001 resolves to
+     * "term_shell", a herdr pane recognised as no configured role, so the real
+     * {@link CallerResolver#observerSendTarget()} classifier reaches the known lead and refuses
+     * the known collaborator -- over the route, not just the unit-level classifier, so a grant
+     * covering only MCP cannot leave this one behind.
+     */
+    @Test
+    void anObserverMaySendToAKnownLeadButNotToAKnownCollaboratorOverRest() throws Exception {
+        int port = startWithRealClassifier(9001L,
+                Map.of("term_lead_known", "lead-x"), Map.of("term_collab_known", "ops2"));
+
+        HttpResponse<String> toLead = send(port, "POST", "/sessions/term_lead_known/message",
+                "{\"content\":\"hi\",\"wait\":false}", null);
+        assertEquals(202, toLead.statusCode(), toLead.body());
+
+        HttpResponse<String> toCollaborator = send(port, "POST", "/sessions/term_collab_known/message",
+                "{\"content\":\"hi\",\"wait\":false}", null);
+        assertEquals(403, toCollaborator.statusCode(), toCollaborator.body());
+    }
+
     /**
      * As {@link #start}, but with explicit lead/collaborator maps and no spawned-member roster, so
      * a test can wire the real {@link CallerResolver#knownLeadOrCollaborator()} classifier instead