BUG: Event delivery and SSE connection lifecycle

[echel0nn]

Labels: bug, events, sse
Severity: S1.

Finding (path:line)	Issue
platform/events/emitter.py:90-91	_drain calls each destination with no try/except -> one destination raising kills delivery to all remaining destinations for that event AND every queued event behind it (silent loss of audit + progress + SSE for the rest of the request)
platform/events/emitter.py:170-183	_redis_stream opens+closes a new redis.from_url() connection per emit -> 200 events = 200 sequential TCP handshakes
platform/tasks/progress.py:140-152	stream_events() is an infinite while True generator with no max-lifetime, no CancelledError handling, no disconnect detection
api/routers/tasks.py:465-495 + scans.py:228-287	SSE generators never call request.is_disconnected() (unlike sse_events.py:97) -> leaked coroutines + stale Redis XREAD slots for abandoned clients
api/events.py:49-51	get_user_queue hands the same queue to a second concurrent SSE connection for one user; the first close deletes it -> the second connection orphaned / events to a dead queue (multi-tab breakage)
api/routers/sse_events.py:30 + api/metrics.py:47-50	No global max-connections guard (per-minute rate limit does not cap concurrent holds -> DoS); the ACTIVE_SSE gauge is never inc/dec'd so there is no visibility to enforce one
platform/events/domain_events.py:1-228	The 10-event catalog has no persistence, no subscriber registry, no dispatch; only LlmCallCompleted is published via an untyped self.bus whose class is absent -> dead code, modules cannot react
tools/aila_fuzz_reporter/__main__.py:118-131 + base.py:212-238	seen_hashes is in-memory only -> every crash re-POSTed after restart; and stack_hash_of() (frame-based dedup) is exported but unused (scrapers hash the filename) -> client/server dedup keys never agree

Acceptance: each destination isolated so one failure does not drop the rest; a pooled Redis connection; SSE generators check disconnect + bound lifetime + handle CancelledError; per-user queue supports concurrent connections; a concurrent-connection cap with a live gauge; domain events wired to a real bus or removed; fuzz dedup persisted and frame-hash aligned with the backend.

[echel0nn]

Implementation-ready design (2026-07-19). Wave 1b. Full design on disk: .run/designs/DESIGN_automation_events_reporting.md (8-heading template: grounded problem, design with signatures+DDL+Alembic, reworked concerns, test plan, rollout).

Key moves:

• Per-destination emitter isolation; pooled redis.
• SSE is_disconnected + max-lifetime + max-connections + live ACTIVE_SSE gauge; per-user-queue concurrency; wire or delete the dead domain-events bus; fuzz dedup persisted + frame-based stack_hash.