fleetd #241: bound the echo match so a real report is never swallowed

Round 1 used plain bidirectional containment. The direction that catches the real bug --
the pane holds the brief plus a status bar, so the scrape contains the brief -- also fires
when a member restates the whole brief and then writes a genuine report under it. That
threw the report away and told the lead nothing was produced, which is worse than the bug
being fixed: it destroys a delivery instead of merely obscuring one.

The safe direction (the scrape is a fragment of the brief) stays unbounded, because a
fragment of the brief is by definition not a report. The dangerous direction now requires
the scrape to add at most MAX_ECHO_EXCESS_CHARS beyond the brief, which is the amount of
TUI chrome a real echo carries.

Work by the cb241 worker, committed by the lead: its backend stopped answering after the
fix was written, so two turns ended with no commit and no reply. Verified by the lead:
1169 tests, 0 failures; removing the bound turns pinsTheMaximumTuiChromeExcess and
completionFallbackKeepsARealReportThatRestatesTheWholeBrief red with 0 compile errors.

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

@@ -390,7 +390,12 @@ public final class Fleetd {
         // now that `sessions` exists to resolve target -> session -> profile.
         exhaustionSinkRef.set(exhaustionSink);
         AgentControl agents = router.memberAgents();
-        CompletionResolver completion = new CompletionResolver(agents, rendezvous, exhaustedPatterns, exhaustionSink);
+        CompletionResolver completion = new CompletionResolver(agents, rendezvous, exhaustedPatterns, exhaustionSink,
+                target -> sessions.roster().stream()
+                        .filter(session -> target.equals(session.terminalId()))
+                        .findFirst()
+                        .map(session -> new CompletionResolver.WorktreeBranch(session.worktree(), session.branch()))
+                        .orElse(null));
         // CB-113: deliver only to an available worker (its MCP is connected), never its boot window.
         // CB-301: the manager's presence bridge records availability and drives SPAWNING → READY.
         MemberPresence presence = sessions.asPresence();

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

@@ -14,6 +14,7 @@ import java.util.TreeSet;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.LongSupplier;
+import java.util.function.Function;
 import java.util.regex.Pattern;
 
 /**
@@ -85,6 +86,17 @@ public final class CompletionResolver implements TurnListener {
     private static final String CLIPPED_PANE_TAIL_MARKER =
             "[Pane tail clipped: member did not call fleet_reply.]";
 
+    /** A pane echo must be this large before it can replace a completion report. */
+    static final int ECHO_MIN_CHARS = 400;
+
+    /** Normalised TUI chrome may add this many characters to an otherwise echoed brief. */
+    static final int MAX_ECHO_EXCESS_CHARS = 160;
+
+    /** The explicit result returned instead of a lead's echoed injected brief. */
+    public static final String NO_REPORT_PREFIX = "[no report — the member ended its turn without fleet_reply, "
+            + "and the pane still shows the injected brief. Nothing was produced on the pane. Check the "
+            + "member's worktree and branch for committed work before re-delegating.";
+
     private final AgentControl agents;
     private final Rendezvous rendezvous;
     private final ExhaustedPatternLookup exhaustedPatterns;
@@ -92,6 +104,11 @@ public final class CompletionResolver implements TurnListener {
     private final BackendErrorPatternLookup backendErrorPatterns;
     private final BackendErrorSink backendErrorSink;
     private final LongSupplier nowNanos;
+    private final Function<String, WorktreeBranch> worktreeBranches;
+
+    /** Known member location, used only to guide a lead after an echoed brief. */
+    public record WorktreeBranch(String worktree, String branch) {
+    }
 
     /**
      * Per-target record of the turn currently in flight: the exact {@link Rendezvous} waiter its
@@ -108,7 +125,8 @@ public final class CompletionResolver implements TurnListener {
      * the other half of the {@link #MIN_TURN_NANOS} floor check, compared against a fresh reading at
      * resolution time.
      */
-    record InFlight(CompletableFuture<Rendezvous.Resolution> waiter, String baseline, long deliveredAtNanos) {
+    record InFlight(CompletableFuture<Rendezvous.Resolution> waiter, String baseline, long deliveredAtNanos,
+                    String injectedText) {
 
         /**
          * Convenience for tests exercising scrape/suppression logic that don't care about turn
@@ -116,7 +134,11 @@ public final class CompletionResolver implements TurnListener {
          * Not used by production code — {@link #captureBaseline} always records a real reading.
          */
         InFlight(CompletableFuture<Rendezvous.Resolution> waiter, String baseline) {
-            this(waiter, baseline, Long.MIN_VALUE / 2);
+            this(waiter, baseline, Long.MIN_VALUE / 2, null);
+        }
+
+        InFlight(CompletableFuture<Rendezvous.Resolution> waiter, String baseline, long deliveredAtNanos) {
+            this(waiter, baseline, deliveredAtNanos, null);
         }
     }
 
@@ -139,11 +161,18 @@ public final class CompletionResolver implements TurnListener {
      * (fleetd#201 Unit 5).
      */
     public CompletionResolver(AgentControl agents, Rendezvous rendezvous, ExhaustedPatternLookup exhaustedPatterns,
-                              ExhaustionSink exhaustionSink) {
+                               ExhaustionSink exhaustionSink) {
         this(agents, rendezvous, exhaustedPatterns, exhaustionSink,
                 BackendErrorPatternLookup.legacy(), BackendErrorSink.none(), System::nanoTime);
     }
 
+    /** Production constructor with a lookup for the member worktree and branch. */
+    public CompletionResolver(AgentControl agents, Rendezvous rendezvous, ExhaustedPatternLookup exhaustedPatterns,
+                              ExhaustionSink exhaustionSink, Function<String, WorktreeBranch> worktreeBranches) {
+        this(agents, rendezvous, exhaustedPatterns, exhaustionSink,
+                BackendErrorPatternLookup.legacy(), BackendErrorSink.none(), System::nanoTime, worktreeBranches);
+    }
+
     /**
      * Transition constructor (fleetd#201 Unit 1): same legacy backend-error defaults as the 4-arg
      * constructor above, but with the injectable clock. Kept so existing fleetd#164 timing tests
@@ -172,7 +201,7 @@ public final class CompletionResolver implements TurnListener {
                        ExhaustionSink exhaustionSink, BackendErrorPatternLookup backendErrorPatterns,
                        BackendErrorSink backendErrorSink) {
         this(agents, rendezvous, exhaustedPatterns, exhaustionSink, backendErrorPatterns, backendErrorSink,
-                System::nanoTime);
+                System::nanoTime, _ -> null);
     }
 
     /**
@@ -185,8 +214,17 @@ public final class CompletionResolver implements TurnListener {
      * package.
      */
     public CompletionResolver(AgentControl agents, Rendezvous rendezvous, ExhaustedPatternLookup exhaustedPatterns,
-                       ExhaustionSink exhaustionSink, BackendErrorPatternLookup backendErrorPatterns,
-                       BackendErrorSink backendErrorSink, LongSupplier nowNanos) {
+                        ExhaustionSink exhaustionSink, BackendErrorPatternLookup backendErrorPatterns,
+                        BackendErrorSink backendErrorSink, LongSupplier nowNanos) {
+        this(agents, rendezvous, exhaustedPatterns, exhaustionSink, backendErrorPatterns, backendErrorSink,
+                nowNanos, _ -> null);
+    }
+
+    /** Full constructor with injectable clock and member location lookup. */
+    public CompletionResolver(AgentControl agents, Rendezvous rendezvous, ExhaustedPatternLookup exhaustedPatterns,
+                        ExhaustionSink exhaustionSink, BackendErrorPatternLookup backendErrorPatterns,
+                        BackendErrorSink backendErrorSink, LongSupplier nowNanos,
+                        Function<String, WorktreeBranch> worktreeBranches) {
         this.agents = agents;
         this.rendezvous = rendezvous;
         this.exhaustedPatterns = Objects.requireNonNull(exhaustedPatterns, "exhaustedPatterns");
@@ -194,6 +232,7 @@ public final class CompletionResolver implements TurnListener {
         this.backendErrorPatterns = Objects.requireNonNull(backendErrorPatterns, "backendErrorPatterns");
         this.backendErrorSink = Objects.requireNonNull(backendErrorSink, "backendErrorSink");
         this.nowNanos = Objects.requireNonNull(nowNanos, "nowNanos");
+        this.worktreeBranches = Objects.requireNonNull(worktreeBranches, "worktreeBranches");
     }
 
     @Override
@@ -223,7 +262,7 @@ public final class CompletionResolver implements TurnListener {
             baseline = null; // fail open: no baseline ⇒ no suppression
             log.debug("delivery baseline for {} failed: {}", target, e.getMessage());
         }
-        inFlight.put(target, new InFlight(waiter, baseline, nowNanos.getAsLong()));
+        inFlight.put(target, new InFlight(waiter, baseline, nowNanos.getAsLong(), token.injectedText()));
     }
 
     /** The turn currently baselined for {@code target}, or {@code null} — a test hook for the captureBaseline path. */
@@ -369,6 +408,9 @@ public final class CompletionResolver implements TurnListener {
             return;
         }
         String completion = clipped ? tail + "\n" + CLIPPED_PANE_TAIL_MARKER : tail;
+        if (echoesInjectedBrief(tail, turn.injectedText())) {
+            completion = noReportMessage(target) + (clipped ? "\n" + CLIPPED_PANE_TAIL_MARKER : "");
+        }
         if (rendezvous.resolveCompletion(waiter, completion)) {
             inFlight.remove(target, turn);
             if (clipped) {
@@ -381,6 +423,40 @@ public final class CompletionResolver implements TurnListener {
         }
     }
 
+    /**
+     * A full echoed brief is at least 400 normalised characters. A scrape that contains the brief may
+     * add no more than 160 normalised characters of TUI chrome. This accepts harmless status text, but
+     * preserves a real report that restates the full brief before adding substantive content.
+     */
+    static boolean echoesInjectedBrief(String scrape, String injectedText) {
+        String normalScrape = normalize(scrape);
+        String normalInjected = normalize(injectedText);
+        if (normalScrape.length() < ECHO_MIN_CHARS || normalInjected.length() < ECHO_MIN_CHARS) {
+            return false;
+        }
+        if (normalInjected.contains(normalScrape)) {
+            return true;
+        }
+        return normalScrape.contains(normalInjected)
+                && normalScrape.length() - normalInjected.length() <= MAX_ECHO_EXCESS_CHARS;
+    }
+
+    private static String normalize(String text) {
+        return text == null ? "" : text.toLowerCase().replaceAll("[^a-z0-9]+", "");
+    }
+
+    private String noReportMessage(String target) {
+        WorktreeBranch location = worktreeBranches.apply(target);
+        if (location == null || (location.worktree() == null && location.branch() == null)) {
+            return NO_REPORT_PREFIX + "]";
+        }
+        String locationText = location.worktree() == null ? "" : " worktree=" + location.worktree();
+        if (location.branch() != null) {
+            locationText += " branch=" + location.branch();
+        }
+        return NO_REPORT_PREFIX + locationText + "]";
+    }
+
     /**
      * fleetd#211: the raw-scrape fallback classification, run only when {@link #lastAssistantBlock}
      * found nothing usable (see the call site in {@link #resolve}). Mirrors the two classifications

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

@@ -10,6 +10,7 @@ import dev.ltms.fleet.herdr.Agent;
 import dev.ltms.fleet.metrics.FleetMetrics;
 import dev.ltms.fleet.metrics.Metrics;
 import dev.ltms.fleet.inject.MemberPresence;
+import dev.ltms.fleet.inject.CompletionResolver;
 import dev.ltms.fleet.herdr.HerdrException;
 import dev.ltms.fleet.msg.LeadChannel;
 import dev.ltms.fleet.msg.LeadMessage;
@@ -543,8 +544,9 @@ public final class FleetMcp {
             case REPLIED -> text(r.text());
             // The worker's turn finished but it never called fleet_reply — hand back the scraped
             // transcript tail, flagged so the primary knows it isn't a structured reply.
-            case COMPLETED_UNREPLIED -> text(
-                    "[worker finished without a structured fleet_reply — transcript tail follows]\n" + r.text());
+            case COMPLETED_UNREPLIED -> text(r.text().startsWith(CompletionResolver.NO_REPORT_PREFIX)
+                    ? r.text()
+                    : "[worker finished without a structured fleet_reply — transcript tail follows]\n" + r.text());
             // The worker ran the turn then wedged (CB-109) — surface the error context.
             case WORKER_FAILED -> text("[worker failed — turn ended in an unrecoverable state]\n" + r.text());
             // The backend refused on a subscription usage limit (CB-578 stage A) — the worker's
@@ -659,6 +661,7 @@ public final class FleetMcp {
         }
         return switch (v.phase()) {
             case DONE -> text(v.replySource() != null && v.replySource().equals("transcript")
+                            && !v.reply().startsWith(CompletionResolver.NO_REPORT_PREFIX)
                     ? "[done — worker finished without a structured fleet_reply; transcript tail follows]\n" + v.reply()
                     : v.reply());
             case PENDING -> text("[pending — " + v.detail() + "]");

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

@@ -746,7 +746,7 @@ public final class MessageService {
                 if (task != null) {
                     asyncTasksByWaiter.put(reply, task);
                 }
-                TurnToken token = new TurnToken(target, reply);
+                TurnToken token = new TurnToken(target, reply, content);
                 // The send has won the lock; the accepted-delivery hook records delegator ownership
                 // here (CB-548). It runs BEFORE enqueue so a throwing hook — onAccepted is now a
                 // public callback — fails the send without queuing a message that would orphan.

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

@@ -9,12 +9,19 @@ import java.util.concurrent.CompletableFuture;
 public final class TurnToken {
     private final String target;
     private final CompletableFuture<Rendezvous.Resolution> waiter;
+    private final String injectedText;
 
     public TurnToken(String target, CompletableFuture<Rendezvous.Resolution> waiter) {
+        this(target, waiter, null);
+    }
+
+    public TurnToken(String target, CompletableFuture<Rendezvous.Resolution> waiter, String injectedText) {
         this.target = target;
         this.waiter = waiter;
+        this.injectedText = injectedText;
     }
 
     public String target() { return target; }
     public CompletableFuture<Rendezvous.Resolution> waiter() { return waiter; }
+    public String injectedText() { return injectedText; }
 }

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

@@ -196,6 +196,26 @@ class CompletionResolverTest {
         assertEquals("complete report", waiter.getNow(null).text());
     }
 
+    @Test
+    void suppressesABareEchoWithOnlyTuiChrome() {
+        String injected = "Load the implementer skill. You own fleetd #999. ".repeat(12);
+        String scrape = injected + "\nDev auto - GPT-5.6 Terra OpenAI";
+
+        assertTrue(CompletionResolver.echoesInjectedBrief(scrape, injected));
+    }
+
+    @Test
+    void pinsTheMaximumTuiChromeExcess() {
+        String injected = "a".repeat(CompletionResolver.ECHO_MIN_CHARS);
+        String underMargin = injected + "b".repeat(CompletionResolver.MAX_ECHO_EXCESS_CHARS);
+        String overMargin = injected + "b".repeat(CompletionResolver.MAX_ECHO_EXCESS_CHARS + 1);
+
+        assertTrue(CompletionResolver.echoesInjectedBrief(underMargin, injected),
+                "the configured excess itself remains an echoed brief");
+        assertFalse(CompletionResolver.echoesInjectedBrief(overMargin, injected),
+                "one character beyond the excess must preserve the scrape as a real report");
+    }
+
     @Test
     void resolvesSynchronouslyBeforePostTurnContextClearing() {
         FakeHerdr herdr = new FakeHerdr().readText("⏺ previous answer\n❯ ");

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

@@ -56,7 +56,11 @@ class MessageServiceTest {
 
     /** Run {@code send} on a background thread; the current thread drives the worker's turn. */
     private CompletableFuture<MessageService.Reply> sendAsync() {
-        return CompletableFuture.supplyAsync(() -> messages.send(T, "do the task", 5000));
+        return sendAsync("do the task");
+    }
+
+    private CompletableFuture<MessageService.Reply> sendAsync(String content) {
+        return CompletableFuture.supplyAsync(() -> messages.send(T, content, 5000));
     }
 
     private void awaitWaiting() throws InterruptedException {
@@ -86,6 +90,94 @@ class MessageServiceTest {
         assertTrue(reply.completed(), "a scraped completion still counts as completed");
     }
 
+    @Test
+    void completionFallbackReplacesAnEchoedInjectedBriefWithNoReportOutcome() throws Exception {
+        String brief = "Implement the requested change. ".repeat(20);
+        CompletableFuture<MessageService.Reply> send = sendAsync(brief);
+        awaitWaiting();
+
+        herdr.readText("$ prompt");
+        injector.onStatus(T, AgentStatus.IDLE);
+        injector.onStatus(T, AgentStatus.WORKING);
+        herdr.readText("⏺ " + brief + "\n❯ ");
+        injector.onStatus(T, AgentStatus.IDLE);
+
+        MessageService.Reply reply = send.get(5, TimeUnit.SECONDS);
+        assertEquals(MessageService.Outcome.COMPLETED_UNREPLIED, reply.outcome());
+        assertEquals(CompletionResolver.NO_REPORT_PREFIX + "]", reply.text(),
+                "the real injector -> completion fallback path must not return the lead's brief");
+    }
+
+    @Test
+    void completionFallbackKeepsARealReportThatRestatesTheWholeBrief() throws Exception {
+        String brief = "Load the implementer skill. You own fleetd #999. ".repeat(12);
+        String report = brief + "\n\n## Report\n"
+                + ("I implemented the fix in GitWorktrees.java, added five tests, ran mvn clean install "
+                + "and got 1168 tests with 0 failures. Commit 321d8dc pushed. ").repeat(8);
+        CompletableFuture<MessageService.Reply> send = sendAsync(brief);
+        awaitWaiting();
+
+        herdr.readText("$ prompt");
+        injector.onStatus(T, AgentStatus.IDLE);
+        injector.onStatus(T, AgentStatus.WORKING);
+        herdr.readText("⏺ " + report + "\n❯ ");
+        injector.onStatus(T, AgentStatus.IDLE);
+
+        MessageService.Reply reply = send.get(5, TimeUnit.SECONDS);
+        assertEquals(MessageService.Outcome.COMPLETED_UNREPLIED, reply.outcome());
+        assertEquals(report.strip(), reply.text(), "a report that restates the whole brief must survive unchanged");
+    }
+
+    @Test
+    void completionFallbackNamesTheKnownWorktreeAndBranchForAnEchoedBrief() throws Exception {
+        FakeHerdr localHerdr = new FakeHerdr();
+        Rendezvous localRendezvous = new Rendezvous();
+        java.util.concurrent.atomic.AtomicLong localClock = new java.util.concurrent.atomic.AtomicLong();
+        CompletionResolver localCompletion = new CompletionResolver(new AgentControl(localHerdr), localRendezvous,
+                ExhaustedPatternLookup.none(), ExhaustionSink.none(),
+                dev.ltms.fleet.inject.BackendErrorPatternLookup.legacy(),
+                dev.ltms.fleet.inject.BackendErrorSink.none(),
+                () -> localClock.addAndGet(CompletionResolver.MIN_TURN_NANOS + 1),
+                target -> new CompletionResolver.WorktreeBranch("/tmp/member-worktree", "worker/cb241"));
+        Injector localInjector = new Injector(new AgentControl(localHerdr), localCompletion);
+        MessageService localMessages = new MessageService(new AgentControl(localHerdr), localInjector,
+                localRendezvous, new InMemoryReplyInbox());
+        String brief = "Implement the requested change. ".repeat(20);
+        CompletableFuture<MessageService.Reply> send =
+                CompletableFuture.supplyAsync(() -> localMessages.send(T, brief, 5000));
+        long deadline = System.currentTimeMillis() + 2000;
+        while (!localRendezvous.isWaiting(T) && System.currentTimeMillis() < deadline) {
+            Thread.sleep(5);
+        }
+        assertTrue(localRendezvous.isWaiting(T));
+
+        localHerdr.readText("$ prompt");
+        localInjector.onStatus(T, AgentStatus.IDLE);
+        localInjector.onStatus(T, AgentStatus.WORKING);
+        localHerdr.readText("⏺ " + brief + "\n❯ ");
+        localInjector.onStatus(T, AgentStatus.IDLE);
+
+        assertEquals(CompletionResolver.NO_REPORT_PREFIX + " worktree=/tmp/member-worktree "
+                        + "branch=worker/cb241]", send.get(5, TimeUnit.SECONDS).text());
+    }
+
+    @Test
+    void completionFallbackKeepsTheClippedMarkerWhenAnEchoedBriefIsTooLong() throws Exception {
+        String brief = "a".repeat(4_001); // CompletionResolver's 4,000-character scrape cap
+        CompletableFuture<MessageService.Reply> send = sendAsync(brief);
+        awaitWaiting();
+
+        herdr.readText("$ prompt");
+        injector.onStatus(T, AgentStatus.IDLE);
+        injector.onStatus(T, AgentStatus.WORKING);
+        herdr.readText("⏺ " + brief + "\n❯ ");
+        injector.onStatus(T, AgentStatus.IDLE);
+
+        assertEquals(CompletionResolver.NO_REPORT_PREFIX + "]\n"
+                        + "[Pane tail clipped: member did not call fleet_reply.]",
+                send.get(5, TimeUnit.SECONDS).text());
+    }
+
     @Test
     void backendErrorScrapeThroughMessageServiceFailsInsteadOfBecomingReplyText() throws Exception {
         // fleetd#164 (part 2 addendum): a scrape that reads cleanly but is only the backend's own