feat: bounty board, task lifecycle, AI work performer flow, notifications (phase 8)

- whitelist HTML sanitizer (stdlib tokenizer) with XSS vector tests
- developer board: pool-scoped visibility, customer/search/minBounty/sort
  filters, stale-task age badges, competing-claims visibility setting,
  saved filters in profile extras
- claims: request/withdraw (developer), approve/decline (consultant) with
  notifications to winners and losers; unassign/abandon back to board
- work tracking: start, sanitized comments with @mention notifications,
  time logging, submit for review
- review queue + review with per-AC checklist stored on the timeline;
  approve writes the immutable bountyAwards row (human assignees only)
- assign-to-AI: §5.2 job submission, HMAC-verified callback endpoint,
  idempotent by jobId, artifacts downloaded into GridFS, failure path
  keeps the task assigned with timeline + notification
- notifications API + bell with unread badge, dropdown, page, WS toasts
- pages: bounty board, my-tasks kanban, task detail (role-driven actions,
  review dialog, AI dialog), review queue, developer pool

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

PROGRESS.md

@@ -8,3 +8,4 @@
 - Phase 5 (admin): customer CRUD wizard with per-system encrypted credentials + test connection (jira/ado/youtrack/demo connectors), user management (roles, disable w/ session revoke, force-reset, delete, self-lockout guards), runtime settings doc, audit log on every privileged mutation + list API, service-status panel (mongo/atomizer/WP health + latency, late-bound breaker/sync/jobs providers), tabbed admin UI - tests green. Fixed mongod WT_PANIC: container nofile ulimit was 1024, raised to 64000 in compose.
 - Phase 6 (sync workers): per-customer pollers with reconcile loop (start/stop/interval changes), §5.3 idempotent upsert keyed (system,key,customerId) w/ content-hash change detection, upstream edits refresh only while imported (timeline+notification after), attachment caching to GridFS, orphan flagging (never deletes), admin sync-now trigger + worker statuses, default budget prefill — demo-type integration tests green.
 - Phase 7 (atomization): circuit breaker (3 fails→open, 60s half-open probe) + retrying bearer JSON client shared by both external services, atomizer client w/ §5.1 coefficient normalization (±0.001 ok, ≤0.05 renormalized, else 502-class), persisted jobs queue (panic-safe, backoff ×3, stale requeue, restart-safe), subdivide/extend endpoints (202 async, re-run replaces unpublished children after confirm), task editing w/ bounty recompute + optional budget cascade, publish single/bulk, WS hub (origin check, 30s heartbeats) + live board, consultant atomization board UI (tree, sliders, sum indicator, modals, shimmer, health gating) — unit + integration green. Fixed tasks unique index: sparse→partial (sparse compound matched every task via customerId).
+- Phase 8 (bounty board + lifecycle): developer board (pool-scoped, filters/search/sort, stale age badges, hide-competing-claims setting, saved filters), claim/withdraw/decline/approve, assign-to-AI via §5.2 client + HMAC-verified idempotent callback w/ artifact ingestion into GridFS, start/submit/abandon/unassign, comments (sanitized, @mentions→notifications), time log, review queue + per-AC checklist on timeline, immutable bountyAwards on approve (humans only), notifications center + bell + WS toasts, my-tasks kanban, task detail page, pool management UI, server-side HTML sanitizer w/ XSS vector tests — full lifecycle integration tests green.