Fix mobile agent terminal state handling

Signed-off-by: kenny lopez <klopez4212@gmail.com>

mobile/lib/features/channels/agent_activity/active_agent_turns.dart

@@ -7,7 +7,9 @@ import 'observer_subscription.dart';
 
 const _defaultLivenessTimeout = Duration(seconds: 30);
 const _activeTurnClockInterval = Duration(seconds: 5);
-const _maximumLivenessInterval = Duration(hours: 24);
+// Matches buzz-acp's MAX_TURN_DURATION_CEILING_SECS. A disabled or unusually
+// sparse liveness cadence must not expire before any legal turn can finish.
+const _maximumTurnDuration = Duration(days: 7);
 const _livenessTimeoutSlack = Duration(seconds: 30);
 
 /// Lifecycle state reconstructed from owner-scoped observer frames.
@@ -114,6 +116,12 @@ List<AgentTurnState> reduceAgentTurnStates(
           if (turnId != null) {
             terminalOrderById[turnId] = frameOrderAt;
             final existing = turnsById[turnId];
+            // The harness's generic completion guard can run after its result
+            // handler emits the specific failure outcome.
+            if (frame.kind == 'turn_completed' &&
+                existing?.phase == AgentTurnPhase.error) {
+              continue;
+            }
             final channelId = existing?.channelId ?? frame.channelId;
             if (channelId == null) continue;
             turnsById[turnId] =
@@ -293,11 +301,11 @@ Duration _livenessTimeout(dynamic payload) {
 
   final intervalSeconds = rawInterval.toInt();
   if (intervalSeconds <= 0) {
-    return _maximumLivenessInterval + _livenessTimeoutSlack;
+    return _maximumTurnDuration + _livenessTimeoutSlack;
   }
   final boundedInterval = intervalSeconds.clamp(
     5,
-    _maximumLivenessInterval.inSeconds,
+    _maximumTurnDuration.inSeconds,
   );
   final timeoutSeconds = boundedInterval + _livenessTimeoutSlack.inSeconds;
   return Duration(

mobile/test/features/channels/agent_activity/active_agent_turns_test.dart

@@ -50,6 +50,26 @@ void main() {
     expect(turns[1].errorMessage, 'Tool permission denied');
   });
 
+  test('keeps an error terminal when generic completion arrives later', () {
+    final turns = reduceAgentTurnStates({
+      'agent-a': [
+        _frame(seq: 1, second: 1, kind: 'turn_started'),
+        _frame(
+          seq: 2,
+          second: 2,
+          kind: 'turn_error',
+          payload: {'error': 'Agent timed out'},
+        ),
+        _frame(seq: 3, second: 3, kind: 'turn_completed'),
+      ],
+    }, now: DateTime.utc(2026, 8, 16, 12, 1));
+
+    expect(turns, hasLength(1));
+    expect(turns.single.phase, AgentTurnPhase.error);
+    expect(turns.single.errorMessage, 'Agent timed out');
+    expect(turns.single.terminalAt, DateTime.utc(2026, 8, 16, 12, 0, 2));
+  });
+
   test('expires silence without claiming the turn finished', () {
     final turns = reduceAgentTurnStates({
       'agent-a': [_frame(seq: 1, second: 1, kind: 'turn_started')],
@@ -84,6 +104,35 @@ void main() {
     expect(afterTimeout, isEmpty);
   });
 
+  test('honors advertised liveness intervals longer than one day', () {
+    final frames = {
+      'agent-a': [
+        _frame(
+          seq: 1,
+          second: 1,
+          kind: 'turn_started',
+          payload: {'livenessIntervalSecs': 48 * 60 * 60},
+        ),
+      ],
+    };
+
+    final beforeTimeout = reduceAgentTurnStates(
+      frames,
+      now: DateTime.utc(2026, 8, 18, 12, 0, 30),
+    );
+    final afterTimeout = reduceAgentTurnStates(
+      frames,
+      now: DateTime.utc(2026, 8, 18, 12, 0, 32),
+    );
+
+    expect(beforeTimeout, hasLength(1));
+    expect(
+      beforeTimeout.single.livenessTimeout,
+      const Duration(hours: 48, seconds: 30),
+    );
+    expect(afterTimeout, isEmpty);
+  });
+
   test('keeps liveness-disabled turns until the bounded crash backstop', () {
     final frames = {
       'agent-a': [
@@ -98,17 +147,17 @@ void main() {
 
     final longRunning = reduceAgentTurnStates(
       frames,
-      now: DateTime.utc(2026, 8, 17, 12),
+      now: DateTime.utc(2026, 8, 23, 12),
     );
     final pastBackstop = reduceAgentTurnStates(
       frames,
-      now: DateTime.utc(2026, 8, 17, 12, 0, 32),
+      now: DateTime.utc(2026, 8, 23, 12, 0, 32),
     );
 
     expect(longRunning, hasLength(1));
     expect(
       longRunning.single.livenessTimeout,
-      const Duration(hours: 24, seconds: 30),
+      const Duration(days: 7, seconds: 30),
     );
     expect(pastBackstop, isEmpty);
   });