feat(cli): websocket client + MCP tool integration

broker-client: full WS client with hello handshake + ack, auto-reconnect
with exponential backoff (1s → 30s capped), in-memory outbound queue
(max 100) during reconnect, 500-entry push buffer for check_messages.

MCP tool integration:
- send_message: "slug:target" prefix or single-mesh fast path
- check_messages: drains push buffers across all clients
- set_status: fans manual override across all connected meshes
- set_summary: stubbed (broker protocol extension needed)
- list_peers: stubbed — lists connected mesh slugs + statuses

manager module holds Map<meshId, BrokerClient>, starts on MCP server
boot for every joined mesh in ~/.claudemesh/config.json.

new CLI command: seed-test-mesh injects a mesh row for dev testing.

also fixes a broker-side hello race: handleHello sent hello_ack before
the caller closure assigned presenceId, so clients sending right after
the ack hit the no_hello check. Fix: return presenceId, caller sets
closure var, THEN sends hello_ack. Queue drain is fire-and-forget now.

round-trip verified: two clients, A→B, push received with correct
senderPubkey + ciphertext. 44/44 broker tests still pass.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/cli/src/commands/seed-test-mesh.ts

@@ -0,0 +1,44 @@
+/**
+ * `claudemesh seed-test-mesh` — dev-only helper for 15b testing.
+ *
+ * Writes a locally-valid JoinedMesh entry to ~/.claudemesh/config.json
+ * so the MCP server can connect to a locally-running broker without
+ * invite-link / crypto plumbing.
+ *
+ * Usage:
+ *   claudemesh seed-test-mesh <broker-url> <mesh-id> <member-id> <pubkey> <slug>
+ */
+
+import { loadConfig, saveConfig } from "../state/config";
+
+export function runSeedTestMesh(args: string[]): void {
+  const [brokerUrl, meshId, memberId, pubkey, slug] = args;
+  if (!brokerUrl || !meshId || !memberId || !pubkey || !slug) {
+    console.error(
+      "Usage: claudemesh seed-test-mesh <broker-ws-url> <mesh-id> <member-id> <pubkey> <slug>",
+    );
+    console.error("");
+    console.error(
+      'Example: claudemesh seed-test-mesh "ws://localhost:7900/ws" mesh-123 member-abc aaa..aaa smoke-test',
+    );
+    process.exit(1);
+  }
+  const config = loadConfig();
+  // Remove any prior entry with same slug (idempotent).
+  config.meshes = config.meshes.filter((m) => m.slug !== slug);
+  config.meshes.push({
+    meshId,
+    memberId,
+    slug,
+    name: `Test: ${slug}`,
+    pubkey,
+    secretKey: "dev-only-stub", // real keypair generated during join in Step 17
+    brokerUrl,
+    joinedAt: new Date().toISOString(),
+  });
+  saveConfig(config);
+  console.log(`Seeded mesh "${slug}" (${meshId}) into local config.`);
+  console.log(
+    `Run \`claudemesh mcp\` to connect, or register with Claude Code via \`claudemesh install\`.`,
+  );
+}