fix: opposite_rearm/rearm alerts + /resume unified + canary-pause UX guards

Trei găuri observate în sesiunea 2026-04-21:

A. _handle_tick nu avea branch pentru reason=opposite_rearm (PRIMED_* ↔
   ARMED_opus) sau reason=rearm (PRIMED_* → ARMED_* aceeași direcție). La
   17:45 yellow a trecut FSM-ul PRIMED_BUY→ARMED_SELL corect, dar zero alert
   pe Telegram. Adaugă helper _emit_arm_alert (DRY cu branch-ul arm existent)
   și două branch-uri noi cu kind=opposite_rearm / kind=rearm.

B. Canary drift se curăța doar cu /resume force — user ușor confundă
   /set_interval cu „relansare" și rămâne în drift-pause (cazul 18:09 azi).
   /resume acum curăță user_paused + canary.resume() într-o singură comandă.
   /resume force rămâne alias acceptat (muscle memory legacy).

C. Heartbeat-ul afișa „activ ARMED_SELL" deși detecția era oprită de 3 ore
   (state FSM înghețat). Extract _build_heartbeat_alert care arată
   „⚠️ pauzat (drift)" + „[drift-pause]" când canary.is_paused.

Guard-uri pentru comenzi când canary e paused:
- /set_interval: refuzat cu warn „Trimite /resume"
- /ss: screenshot trimis + body-ul include „⚠️ DETECȚIE OPRITĂ"

11 teste noi (1 critical regression pentru bug-ul A observat azi), plus
actualizarea test-ului /resume existent care aserta vechiul comportament.
Total: 235 passed + 8 scenarii regresie.

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

tests/test_main.py

@@ -558,7 +558,7 @@ def _oh_cfg(enabled=True, weekdays=("MON", "TUE", "WED", "THU", "FRI"),
         stop_hhmm=stop,
         _tz_cache=_ZI(tz) if enabled else None,
     )
-    return types.SimpleNamespace(operating_hours=oh)
+    return types.SimpleNamespace(operating_hours=oh, window_title=None)
 
 
 def _fake_canary(paused=False):
@@ -841,8 +841,10 @@ async def test_resume_clears_user_paused_and_canary_when_forced():
 
 
 @pytest.mark.asyncio
-async def test_resume_during_drift_keeps_canary_paused_without_force():
-    """R2 #21: plain /resume during drift clears user_paused but NOT canary."""
+async def test_resume_plain_also_clears_canary_drift():
+    """2026-04-21 decision: /resume (no arg) now clears BOTH user_paused and
+    canary drift. /resume force remains accepted as legacy alias. Previous
+    behavior (force required for drift) was a UX trap — see plan doc."""
     import atm.main as _main
     from atm.commands import Command
 
@@ -859,15 +861,37 @@ async def test_resume_during_drift_keeps_canary_paused_without_force():
     await _main._dispatch_command(ctx, Command(action="resume"))  # no force
 
     assert ctx.lifecycle.user_paused is False
-    assert canary.is_paused is True  # still drift-paused
-    # Message must mention drift
+    assert canary.is_paused is False  # drift cleared without force
+    # Audit event still records was_drift + force=False for traceability
+    resumed = [e for e in ctx.audit.events if e.get("event") == "user_resumed"]
+    assert resumed and resumed[0]["was_drift"] is True and resumed[0]["force"] is False
+    # Message mentions drift-pause was cleared
     status = [a for a in ctx.notifier.alerts if a.kind == "status"]
     assert status and ("drift" in (status[0].title + status[0].body).lower())
 
-    # Now force
-    ctx.notifier.alerts.clear()
+
+@pytest.mark.asyncio
+async def test_resume_force_alias_still_works():
+    """/resume force (value=1) remains accepted — legacy muscle memory."""
+    import atm.main as _main
+    from atm.commands import Command
+
+    class _Canary:
+        def __init__(self): self._p = True
+        @property
+        def is_paused(self): return self._p
+        def resume(self): self._p = False
+    canary = _Canary()
+
+    ctx = _dispatch_ctx(canary=canary)
+    ctx.lifecycle.user_paused = True
+
     await _main._dispatch_command(ctx, Command(action="resume", value=1))
+
+    assert ctx.lifecycle.user_paused is False
     assert canary.is_paused is False
+    resumed = [e for e in ctx.audit.events if e.get("event") == "user_resumed"]
+    assert resumed and resumed[0]["force"] is True
 
 
 @pytest.mark.asyncio
@@ -923,6 +947,85 @@ async def test_status_command_reports_pause_reason():
     assert "pauză manuală" in body or "pauza" in body.lower()
 
 
+@pytest.mark.asyncio
+async def test_set_interval_refused_while_canary_paused():
+    """2026-04-21: /set_interval must not start scheduler while canary is drift-paused.
+    Previously started scheduler silently, misleading the user into thinking
+    detection was live. Now emits a warn and refuses."""
+    import atm.main as _main
+    from atm.commands import Command
+
+    canary = types.SimpleNamespace(is_paused=True, resume=lambda: None)
+    ctx = _dispatch_ctx(canary=canary)
+
+    await _main._dispatch_command(ctx, Command(action="set_interval", value=60))
+
+    # Scheduler must NOT have started
+    assert ctx.scheduler.is_running is False
+    # No scheduler_started audit event
+    assert not any(e.get("event") == "scheduler_started" for e in ctx.audit.events)
+    # A warn alert must have been sent referencing /resume
+    warns = [a for a in ctx.notifier.alerts if a.kind == "warn"]
+    assert warns
+    combined = (warns[0].title + warns[0].body).lower()
+    assert "drift" in combined and "/resume" in combined
+
+
+@pytest.mark.asyncio
+async def test_ss_includes_warn_body_while_canary_paused(monkeypatch, tmp_path):
+    """2026-04-21: /ss still captures while canary is paused, but the alert body
+    must warn that detection is off."""
+    import atm.main as _main
+    from atm.commands import Command
+
+    canary = types.SimpleNamespace(is_paused=True, resume=lambda: None)
+    ctx = _dispatch_ctx(canary=canary)
+
+    # Bypass window focus + use a simple non-None capture result
+    fake_frame = object()
+    ctx = types.SimpleNamespace(**{**ctx.__dict__})  # shallow copy RunContext fields
+    # Simpler: just override the capture and save functions used
+    async_capture_called = {"n": 0}
+    def _capture():
+        async_capture_called["n"] += 1
+        return fake_frame
+    ctx.capture = _capture
+    ctx.fires_dir = tmp_path
+    # window_title off so we skip focus branch
+    ctx.cfg.window_title = None
+    # stub _save_annotated_frame to return a dummy path
+    monkeypatch.setattr(_main, "_save_annotated_frame",
+                        lambda *a, **kw: tmp_path / "fake_ss.png")
+
+    await _main._dispatch_command(ctx, Command(action="ss"))
+
+    screenshots = [a for a in ctx.notifier.alerts if a.kind == "screenshot"]
+    assert screenshots
+    assert "DETECȚIE OPRITĂ" in screenshots[0].body or "drift" in screenshots[0].body.lower()
+    assert "/resume" in screenshots[0].body
+
+
+@pytest.mark.asyncio
+async def test_ss_no_warn_when_canary_healthy(monkeypatch, tmp_path):
+    """/ss body must be empty when canary is not paused (no warn noise)."""
+    import atm.main as _main
+    from atm.commands import Command
+
+    canary = types.SimpleNamespace(is_paused=False, resume=lambda: None)
+    ctx = _dispatch_ctx(canary=canary)
+    ctx.capture = lambda: object()
+    ctx.fires_dir = tmp_path
+    ctx.cfg.window_title = None
+    monkeypatch.setattr(_main, "_save_annotated_frame",
+                        lambda *a, **kw: tmp_path / "fake_ss.png")
+
+    await _main._dispatch_command(ctx, Command(action="ss"))
+
+    screenshots = [a for a in ctx.notifier.alerts if a.kind == "screenshot"]
+    assert screenshots
+    assert screenshots[0].body == ""
+
+
 @pytest.mark.asyncio
 async def test_lifecycle_with_drift_then_resume_then_fire(monkeypatch, tmp_path):
     """E2E #16: drift paused → /resume force → dark_red/light_red produce FIRE alert.
@@ -1040,6 +1143,32 @@ def test_heartbeat_suppressed_outside_hours(monkeypatch):
     assert sent == []
 
 
+def test_build_heartbeat_alert_active_when_not_paused():
+    """Healthy state → title=activ, body shows fsm.state plainly."""
+    import atm.main as _main
+    a = _main._build_heartbeat_alert(
+        fsm_state="ARMED_BUY", fire_count=2, uptime_h=1.5, canary_paused=False,
+    )
+    assert a.kind == "heartbeat"
+    assert a.title == "activ"
+    assert "ARMED_BUY" in a.body
+    assert "[drift-pause]" not in a.body
+    assert "semnale: 2" in a.body
+
+
+def test_build_heartbeat_alert_paused_when_canary_drift():
+    """2026-04-21: heartbeat must reflect canary drift instead of lying with 'activ'."""
+    import atm.main as _main
+    a = _main._build_heartbeat_alert(
+        fsm_state="ARMED_SELL", fire_count=0, uptime_h=3.2, canary_paused=True,
+    )
+    assert a.kind == "heartbeat"
+    assert "pauzat" in a.title
+    assert "drift" in a.title.lower()
+    assert "ARMED_SELL" in a.body
+    assert "[drift-pause]" in a.body
+
+
 @pytest.mark.asyncio
 async def test_status_compact_active():
     """/status produces compact 2-line format; 'Canary' absent."""