feat(phase974): guild mesh stability log filter keys journey stub

Add runGuildMeshStabilityLogFilterKeysJourney for Phase 974 CI bundle.
Non-breaking headless helper; no mesh path behavior change.

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

README.md

@@ -2,6 +2,8 @@
 
 Agent control plane for Pearcord — send the same IPC messages the UI sends, read `view` snapshots, and run scripted journeys against a **live worker** or an in-process **headless** session.
 
+**Phase 974 (v0.8.941):** `runGuildMeshStabilityLogFilterKeysJourney` (dev-log mesh-stability filter key registry journey). Bundle: `npm run test:ci-phase974`.
+
 **Phase 973 (v0.8.940):** `runGuildMeshStabilityIpcContractJourney` (mesh stability IPC contract response builders). Bundle: `npm run test:ci-phase973`.
 
 **Phase 972 (v0.8.939):** `runGuildMeshViewStabilityFieldsJourney` (view meshStabilityStats field registry journey). Bundle: `npm run test:ci-phase972`.

headless.js

@@ -1817,6 +1817,39 @@ class HeadlessSession {
     return { multi, federation }
   }
 
+  /** Journey stub: guild mesh dev-log stability filter keys (Phase 974). */
+  async runGuildMeshStabilityLogFilterKeysJourney (guildId) {
+    if (!this.platform) throw new Error('headless not started')
+    const gid = guildId || this.platform.guild?.guild?.id
+    if (!gid) throw new Error('no guild')
+    const {
+      MESH_STABILITY_DEV_LOG_FILTER,
+      listMeshStabilityLogFilterMessageKeys,
+      matchesMeshStabilityDevLogFilter,
+      buildMeshStabilityLogFilterMessagePattern
+    } = require('pearcord-platform/guild-mesh-stability-log-filter-keys')
+    const levelRank = { trace: 0, debug: 1, info: 2, warn: 3, error: 4 }
+    const keys = listMeshStabilityLogFilterMessageKeys()
+    const pattern = buildMeshStabilityLogFilterMessagePattern()
+    const matchOk = matchesMeshStabilityDevLogFilter(
+      { scope: 'platform.guild', msg: 'guild.mesh.stability', level: 'info' },
+      levelRank
+    )
+    const matchReject = matchesMeshStabilityDevLogFilter(
+      { scope: 'platform.guild', msg: 'guild.mesh.churn', level: 'info' },
+      levelRank
+    )
+    await this.refreshView()
+    return {
+      guildId: gid,
+      filter: MESH_STABILITY_DEV_LOG_FILTER,
+      keys,
+      patternSource: pattern.source,
+      matchOk,
+      matchReject: !matchReject
+    }
+  }
+
   /** Journey stub: guild mesh stability IPC contract (Phase 973). */
   async runGuildMeshStabilityIpcContractJourney (guildId) {
     if (!this.platform) throw new Error('headless not started')