feat(plugin): wire PresenceSync into gateway_start lifecycle (Phase 1.5)

Completes the Phase 1 hand-off chain — HF status now actually reaches
Fabric.Backend.Guild and busy-discard on announce channels becomes
operational end-to-end.

inbound.ts:
- Add getPresenceAccounts() — returns per-agent {agentId, fabricUserId,
  guildBaseUrl, fabricApiKey} for every agent that successfully logged
  in. fabricUserId comes from session.user.id cached on the identity
  registry; guildBaseUrl from session.guilds[0].endpoint captured in a
  new private firstGuildEndpointByAgent map during connectAgent().
- Multi-guild presence is deferred; the first guild per agent is the
  push target. For sim/prod-v1 each agent is in one guild so this is a
  no-op simplification.

index.ts gateway_start:
- After inbound.start() resolves, instantiate PresenceSync, call
  setAccounts(inbound.getPresenceAccounts()), start().
- 5-min refresh timer re-harvests accounts (catches agents added via
  tool-based identity registration AFTER initial start — e.g.
  recruitment flow). setAccounts is idempotent.
- gateway_stop now clears the refresh timer and stops PresenceSync
  before stopping inbound.

End-to-end check (still need sim verification):
  HF plugin scheduler heartbeat -> globalThis.__hfAgentStatus
   -> PresenceSync tick (30s) -> PUT /agents/:uid/presence
   -> agent_presences row -> computeDelivery for xType=announce
   -> busy recipients skipped, idle recipients get observer delivery.

Type-check: only pre-existing openclaw/* runtime-resolved-by-jiti
errors remain; new presence wiring compiles clean.

See DIALECTIC-V2-DESIGN.md section 10 Phase 1 (deferred items now
landed).

src/inbound.ts

@@ -263,8 +263,52 @@ export class FabricInbound {
     this.sockets = [];
   }
 
+  /**
+   * Per-account metadata harvested during `start()` — used by
+   * PresenceSync to know where to push each agent's HF status.
+   *
+   * `fabricUserId` is filled from `session.user.id` after agent-login.
+   * `guildBaseUrl` is the FIRST guild the agent is connected to (multi-
+   * guild presence push is a future concern; for sim/prod-v1 each agent
+   * is in one guild).
+   *
+   * Returns ONLY agents that successfully connected — failed-login
+   * agents have no fabricUserId yet and are excluded.
+   */
+  getPresenceAccounts(): Array<{
+    agentId: string;
+    fabricUserId: string;
+    guildBaseUrl: string;
+    fabricApiKey: string;
+  }> {
+    const out: Array<{ agentId: string; fabricUserId: string; guildBaseUrl: string; fabricApiKey: string }> = [];
+    for (const entry of this.identity.list()) {
+      if (!entry.fabricUserId) continue;
+      const presenceGuildUrl = this.firstGuildEndpointByAgent.get(entry.agentId);
+      if (!presenceGuildUrl) continue;
+      out.push({
+        agentId: entry.agentId,
+        fabricUserId: entry.fabricUserId,
+        guildBaseUrl: presenceGuildUrl,
+        fabricApiKey: entry.fabricApiKey,
+      });
+    }
+    return out;
+  }
+
+  // Filled by connectAgent for each (agent, guild). Tracks ONLY the first
+  // guild per agent (used as the presence-push target).
+  private firstGuildEndpointByAgent = new Map<string, string>();
+
   private async connectAgent(agentId: string, session: FabricSession): Promise<void> {
     const selfUserId = session.user.id;
+    // First-guild capture for presence-sync push target. session.guilds is
+    // already in priority order from Center; we take the first one with a
+    // valid endpoint and stop. Multi-guild presence is a future concern.
+    if (!this.firstGuildEndpointByAgent.has(agentId)) {
+      const firstGuild = session.guilds.find((g) => typeof g.endpoint === 'string' && g.endpoint.length > 0);
+      if (firstGuild) this.firstGuildEndpointByAgent.set(agentId, firstGuild.endpoint);
+    }
     for (const g of session.guilds) {
       const tok = session.guildAccessTokens.find((t) => t.guildNodeId === g.nodeId)?.token;
       if (!tok) continue;