docs(phase974): guild mesh dev-log stability filter keys + v0.8.941

Mark Phase 974 complete (47/50). Update roadmap, release notes, CI docs,
and mesh stability references for log filter keys extract.

Co-authored-by: Cursor <[email protected]>

release_notes/RELEASE_v0.8.941.md

@@ -0,0 +1,42 @@
+# Release v0.8.941 — Phase 974: Guild Mesh Dev-Log Stability Filter Keys Extract
+
+**Date:** 2026-06-05
+**Type:** Non-breaking refactor — Guild mesh production hardening
+
+## Summary
+
+Phase 974 centralises the dev-log **mesh-stability** filter id, message key registry,
+and matcher into `guild-mesh-stability-log-filter-keys.js`. `app.js` adopts the module
+for `devLogPassesFilter` without changing which log lines pass the filter.
+
+## New Module
+
+### `pearcord-platform/guild-mesh-stability-log-filter-keys`
+
+Exports:
+
+- **Constant**: `MESH_STABILITY_DEV_LOG_FILTER` (`mesh-stability`)
+- **Key registry**: `meshStabilityLogFilterMessageKeys` (5 message pattern keys)
+- **Listers**: `listMeshStabilityLogFilterMessageKeys`
+- **Pattern**: `buildMeshStabilityLogFilterMessagePattern`
+- **Matcher**: `matchesMeshStabilityDevLogFilter(record, levelRank, minLevel?)`
+
+## Call-site Wiring (non-breaking)
+
+| File | Change |
+|------|--------|
+| `apps/pearcord/ui/app.js` | Mesh-stability dev-log filter delegates to `matchesMeshStabilityDevLogFilter` |
+
+## Test Coverage
+
+- `smoke-guild-mesh-stability-log-filter-keys-build.cjs` — filter key unit + app.js wire checks
+- `smoke-dev-log-mesh-stability-filter.cjs` — dev-log filter structural smoke
+- `smoke-phase974-boot-gate.cjs` — structural verification + version check (0.8.941)
+- `smoke-agentctl-guild-mesh-stability-log-filter-keys-journey-stub.cjs` — agentctl integration stub
+- `test:mesh-stability-stats` — extended with log filter key assertions
+- `test:gossip-rpc-pull-unit` — extended with log filter matcher assertions
+- `test:ci-phase974` — full CI bundle
+
+## Version
+
+`0.8.940` → `0.8.941`