feat(run): screenshot attach, Telegram ok:false fix, post-FIRE catchup guard

Three bundled fixes on the dispatch + FSM + notifier triangle:

1. Telegram silent-success bug: parse JSON body after 200 OK, raise on
   ok:false so FanoutNotifier retries + DLQs + stats surface the failure.
   Previously Discord succeeded while Telegram silently dropped.

2. Per-kind screenshot attach: new AlertsCfg dataclass with per-kind toggle
   (late_start, catchup, arm, prime, trigger). _save_annotated_frame helper
   extracted from inline FIRE block, threaded via Snapshot closure into
   _handle_tick. Failures audit-logged, never silent.

3. Post-FIRE catchup regression (d7305fb): residual dark_green/dark_red dots
   after a FIRE cycle look like startup-catchup from (color, state) alone.
   New fsm.fired_in_session(direction) gate suppresses synth-arm after a
   cycle already fired in that direction. Opposite direction unaffected.

Also: queue-overflow on_drop audit callback, periodic + shutdown heartbeat
stats per-backend, config back-compat (bool or dict for attach_screenshots).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

configs/example.toml

@@ -80,3 +80,12 @@ low_conf_threshold = 0.2
 low_conf_run = 3
 phaseb_timeout_s = 600
 dead_letter_path = "logs/dead_letter.jsonl"
+
+# Per-kind screenshot-attach toggles. All default to true on upgrade.
+# Accepts either a bare bool (legacy: attach_screenshots = true) or this table.
+[options.attach_screenshots]
+late_start = true   # screenshot on startup-late alerts
+catchup    = true   # screenshot on mid-session catchup arm + prime
+arm        = true   # screenshot on normal arm (turquoise/yellow) — noisiest
+prime      = true   # screenshot on normal prime (dark_green/dark_red)
+trigger    = true   # screenshot on FIRE