feat: agent-to-agent platform on ZeroClaw 0.8.2 — rooms, delegation, A2A ingress

Builds on the v0.8.2 runtime. Four workstreams, all behind the §15 MCP door:

- Group rooms (Phase 1): migration 0026; N-way threads repo with a DM/room
  count-guard; chat.send {room} + room.create/invite/leave tools; RoomMessage
  -> room.message SSE; /api/claw-chat/rooms* APIs; Observer room badge.
- Per-claw door identity: door caller_agent resolves the X-ZeroClaw-Agent
  header (set by the fork) to the specific claw, falling back to roster[0].
- Gated delegation bridge (Phase 3): clawmates__delegate door tool drives a
  sibling via the existing /ws/chat ZeroClawDriveExecutor (not A2A); self-deny,
  per-workspace hourly budget, audit trail, untrusted-banner result. Native
  in-daemon delegation stays off (it would bypass the door).
- A2A tenant ingress (Phase 2): migration 0027 (workspace_a2a + a2a_tokens);
  runtime_provision enable_a2a_server/publish_claw; routes/a2a.rs tenant-aware
  proxy (per-workspace tokens, injected internal bearer, daemon stays internal,
  cards URL-rewritten to the cm-api edge); a2a.invoked taxonomy.

Tests: cm-db room repos, cm-runtime chat tools, door units. sqlx cache updated.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

frontend/src/lib/live/taxonomy.ts

@@ -33,6 +33,17 @@ export interface TaxonomyEvents {
   "door.resolve": { doorId: string; decision: "approve" | "deny"; by?: string };
   /** Observe System → INTER-AGENT COMMS; World → message-in-flight on a connector. */
   "agent.message": { fromAgentId: string; toAgentId: string; text: string; ts?: string };
+  /** Observe → INTER-AGENT COMMS; a message posted to an N-way group room. */
+  "room.message": {
+    fromAgentId: string;
+    threadId: string;
+    subject?: string;
+    text: string;
+    participantIds: string[];
+    ts?: string;
+  };
+  /** Observe → an external A2A caller invoked this agent (a new ingress). */
+  "a2a.invoked": { agentId: string; caller?: string; skill?: string; ts?: string };
   /** World → Live (Gource): the agent pawn retargets to nodeId and beams. */
   "world.touch": { agentId: string; nodeId: string; kind?: "service" | "event"; weight?: number };
   /** World → node glow/pulse intensity. */
@@ -73,6 +84,8 @@ export const TAXONOMY_TYPES: TaxonomyType[] = [
   "door.request",
   "door.resolve",
   "agent.message",
+  "room.message",
+  "a2a.invoked",
   "world.touch",
   "node.activity",
   "topology.update",