snapshot: WIP 5j replay reliability (B1 watchdog + dialog handlers + grounding drift)

Snapshot avant correction du blocage relance Léa (3 incidents 24h: SSH refusé,
polls morts ×2). Point de rollback stable.

Contenu:
- agent_v1/core/executor.py: 5 patchs dialog handling (saveas drift, close_tab
  hotkey fallback, confirm_save Unicode apostrophe, foreground dialog
  recontextualization, runtime_dialog in-loop) + helpers normalize_window_hint,
  requires_post_verify_window_transition
- agent_v1/core/grounding.py: garde drift template fix (fallback_x/y plumbed)
- server_v1/replay_watchdog.py (NEW): orphan watchdog B1, scan 10s timeout 30s
- server_v1/api_stream.py: dispatched_action plumbing, watchdog lifespan,
  metrics endpoint
- server_v1/replay_engine.py: _schedule_retry préserve original_action +
  dispatched_action
- stream_processor.py: gardes _infer_tab_switch_target (no false switch_tab
  on save_as dialog open) + _attach_expected_window_before
- tests/integration: test_replay_watchdog.py (8 cas), test_stream_processor.py
- tests/unit: test_executor_verify_window_guard.py (start_button, close_tab,
  runtime_dialog, post_verify, transition fallbacks)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

agent_v0/server_v1/replay_verifier.py

@@ -328,10 +328,11 @@ class ReplayVerifier:
                 ),
             )
 
-        # Cas 4 : Pas de changement (key_combo, wait)
-        # Pour les raccourcis clavier et attentes, l'absence de changement
-        # n'est pas forcément un problème (ex: Ctrl+C ne change pas l'écran)
-        if action_type in ("key_combo", "wait"):
+        # Cas 4 : Pas de changement (key_combo, wait, verify_screen)
+        # `verify_screen` côté agent n'est qu'une temporisation de stabilisation.
+        # Il ne doit pas exiger un NOUVEAU changement visuel sinon le setup
+        # boucle inutilement une fois l'application déjà ouverte.
+        if action_type in ("key_combo", "wait", "verify_screen"):
             return VerificationResult(
                 verified=True,
                 confidence=0.4,