CB-118: clip the completion baseline so the CB-115 guard survives >cap blocks

captureBaseline stored the raw, unclipped last-assistant block while resolve()
compares against clip(...) capped at MAX_SCRAPE_CHARS. For a block longer than
4000 chars the two capped representations never match even when the pane is
unchanged, defeating the CB-115 misattribution guard and letting a stale
completion resolve a rapid back-to-back send. Clip the baseline identically.

Regression test: an unchanged >cap block stays suppressed.

Surfaced by the fan-out issue-hunt E2E (1 primary -> 3 concurrent workers,
e2e/issue_hunt_test.py, added here). The same hunt's WorkerService.stop() and
Rendezvous.complete() findings were verified as false positives (locatePane is
already guarded; the sender's finally-close already removes the waiter).

Closes #2

bridged/src/main/java/dev/ltms/bridged/inject/CompletionResolver.java

@@ -97,7 +97,11 @@ public final class CompletionResolver implements TurnListener {
         }
         String baseline;
         try {
-            baseline = lastAssistantBlock(agents.read(target, SCRAPE_SOURCE));
+            // Clip to the same cap resolve() applies to the tail (line ~134): the CB-115 misattribution
+            // guard compares baseline.equals(tail), so both sides must be the same capped representation.
+            // An unclipped baseline vs a clipped tail would never match for a >MAX_SCRAPE_CHARS block,
+            // defeating the guard and letting a stale completion resolve the send.
+            baseline = clip(lastAssistantBlock(agents.read(target, SCRAPE_SOURCE)));
         } catch (RuntimeException e) {
             baseline = null; // fail open: no baseline ⇒ no suppression
             log.debug("delivery baseline for {} failed: {}", target, e.getMessage());
@@ -105,6 +109,11 @@ public final class CompletionResolver implements TurnListener {
         inFlight.put(target, new InFlight(waiter, baseline));
     }
 
+    /** The turn currently baselined for {@code target}, or {@code null} — a test hook for the captureBaseline path. */
+    InFlight inFlight(String target) {
+        return inFlight.get(target);
+    }
+
     @Override
     public void onTurnComplete(String target) {
         // Read the in-flight turn on the poller thread — before any next-turn delivery can overwrite