chore: convert plugin to ESM and migrate to current openclaw plugin SDK

ESM conversion:
- plugin/package.json: add "type": "module".
- plugin/tsconfig.json: switch module/moduleResolution to "nodenext"; bump
  target to ES2022.
- All relative imports across plugin/ now carry .js extensions as required
  by Node ESM (nodenext module resolution).
- plugin/index.ts: replace `require('./calendar/schedule-cache')` with a
  proper top-level import; switch `from 'os'` to `from 'node:os'`.

Plugin SDK convention update:
- Wrap default export with definePluginEntry({ id, name, description,
  register }) per the current openclaw plugin authoring contract.
- Modernize plugin/openclaw.plugin.json: drop entry/version, add
  activation.onStartup so gateway_start fires for this plugin at boot,
  declare contracts.tools listing the five harborforge_* tools.
- Add a local plugin/openclaw-sdk.d.ts with ambient declarations for the
  focused subpaths (openclaw/plugin-sdk/plugin-entry,
  openclaw/plugin-sdk/core). We deliberately do NOT add openclaw as an
  npm devDependency: the installer's `npm install --omit=dev` step trips
  over openclaw's own (deeply nested) dependency graph when listed via
  file:.../openclaw, and the runtime contract is provided by the gateway
  loader anyway.
- The local PluginAPI interface is preserved (broader than the standard
  OpenClawPluginApi — it surfaces `version`/`runtime`/`spawn`); the
  register function is cast at the definePluginEntry boundary.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

plugin/index.ts

@@ -11,18 +11,20 @@
  * served directly by the plugin when Monitor queries via the
  * local monitor_port communication path.
  */
-import { hostname, freemem, totalmem, uptime, loadavg, platform } from 'os';
-import { getPluginConfig } from './core/config';
-import { MonitorBridgeClient, type OpenClawMeta } from './core/monitor-bridge';
-import type { OpenClawAgentInfo } from './core/openclaw-agents';
-import { registerGatewayStartHook } from './hooks/gateway-start';
-import { registerGatewayStopHook } from './hooks/gateway-stop';
+import { hostname, freemem, totalmem, uptime, loadavg, platform } from 'node:os';
+import { definePluginEntry } from 'openclaw/plugin-sdk/plugin-entry';
+import { MultiAgentScheduleCache } from './calendar/schedule-cache.js';
+import { getPluginConfig } from './core/config.js';
+import { MonitorBridgeClient, type OpenClawMeta } from './core/monitor-bridge.js';
+import type { OpenClawAgentInfo } from './core/openclaw-agents.js';
+import { registerGatewayStartHook } from './hooks/gateway-start.js';
+import { registerGatewayStopHook } from './hooks/gateway-stop.js';
 import {
   createCalendarBridgeClient,
   createCalendarScheduler,
   CalendarScheduler,
   AgentWakeContext,
-} from './calendar';
+} from './calendar/index.js';
 
 interface PluginAPI {
   logger: {
@@ -53,10 +55,7 @@ interface PluginAPI {
   getAgentStatus?: () => Promise<{ status: string } | null>;
 }
 
-export default {
-  id: 'harbor-forge',
-  name: 'HarborForge',
-  register(api: PluginAPI) {
+function register(api: PluginAPI): void {
     const logger = api.logger || {
       info: (...args: any[]) => console.log('[HarborForge]', ...args),
       error: (...args: any[]) => console.error('[HarborForge]', ...args),
@@ -290,7 +289,6 @@ export default {
       );
 
       // Multi-agent sync + check loop
-      const { MultiAgentScheduleCache } = require('./calendar/schedule-cache') as typeof import('./calendar/schedule-cache');
       const scheduleCache = new MultiAgentScheduleCache();
 
       const SYNC_INTERVAL_MS = 300_000; // 5 min
@@ -595,5 +593,16 @@ export default {
     }));
 
     logger.info('HarborForge plugin registered (id: harbor-forge)');
-  },
-};
+}
+
+// HarborForge's local PluginAPI is broader than the standard OpenClawPluginApi
+// (it surfaces optional `version`/`runtime`/`spawn` accessors that older
+// OpenClaw builds exposed). The cast at the definePluginEntry boundary
+// acknowledges that gap — the runtime api object is whatever the gateway
+// passes us, and each access is guarded with optional chaining / fallbacks.
+export default definePluginEntry({
+  id: 'harbor-forge',
+  name: 'HarborForge',
+  description: 'HarborForge plugin for OpenClaw - project management, monitoring, and CLI integration',
+  register: register as (api: any) => void,
+});