feat(mcp): contracts, capability stats migration and MCP SDK dependency

- contracts/mcp.ts: capability stats/tools, MCP server status/config schemas, mcpToolVisible
- api.ts: GET /capabilities/stats, GET /capabilities/tools, GET /mcp/status, PATCH /mcp/config
- migration 0039: mcp_server_config single row + audit_event capability index
- deno.json: npm:@modelcontextprotocol/[email protected].1

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/db/test/schema.test.ts

@@ -109,6 +109,8 @@ const EXPECTED_TABLES = [
   // W9-I 进程心跳(0034)
   "process_heartbeat",
   "process_heartbeat_sample",
+  // AG-1 MCP 服务端配置(0039)
+  "mcp_server_config",
   // C1-B 恢复码 / Passkey / WebAuthn 挑战(0037)
   "admin_recovery_code",
   "admin_passkey",
@@ -132,6 +134,8 @@ const NON_ENTITY_TABLES = [
   // 进程心跳:instance_id 主键 / 只追加的采样
   "process_heartbeat",
   "process_heartbeat_sample",
+  // 单行配置(id = 1)
+  "mcp_server_config",
   // 一次性凭据:只记创建 / 用掉的时间
   "admin_recovery_code",
   "webauthn_challenge",