feat: implement OpenClaw integration

Ports the OMX OpenClaw module into oh-my-openagent as a first-class integration.
This integration allows forwarding internal events (session lifecycle, tool execution) to external gateways (HTTP or command-based).

- Added `src/openclaw` directory with implementation:
  - `dispatcher.ts`: Handles HTTP/Command dispatching with interpolation
  - `types.ts`: TypeScript definitions
  - `client.ts`: Main entry point `wakeOpenClaw`
  - `index.ts`: Public API
- Added `src/config/schema/openclaw.ts` for Zod schema validation
- Updated `src/config/schema/oh-my-opencode-config.ts` to include `openclaw` config
- Added `src/hooks/openclaw-sender/index.ts` to listen for events
- Registered the hook in `src/plugin/hooks/create-session-hooks.ts`
- Added unit tests in `src/openclaw/__tests__`

Events handled:
- `session-start` (via `session.created`)
- `session-end` (via `session.deleted`)
- `session-idle` (via `session.idle`)
- `ask-user-question` (via `tool.execute.before` for `ask_user_question`)
- `stop` (via `tool.execute.before` for `stop-continuation` command)

src/plugin/event.ts

@@ -215,6 +215,7 @@ export function createEventHandler(args: {
     await Promise.resolve(hooks.compactionTodoPreserver?.event?.(input));
     await Promise.resolve(hooks.writeExistingFileGuard?.event?.(input));
     await Promise.resolve(hooks.atlasHook?.handler?.(input));
+    await Promise.resolve(hooks.openclawSender?.event?.(input));
     await Promise.resolve(hooks.autoSlashCommand?.event?.(input));
   };