Refactor error handling to use platform-specific worker restart instructions

- Updated multiple hooks (context-hook, new-hook, save-hook, summary-hook, user-message-hook) to throw errors using `getWorkerRestartInstructions` for improved user guidance on worker connection issues.
- Enhanced `handleWorkerError` function to utilize the new error message generator for consistent error reporting.
- Modified `ensureWorkerRunning` function to provide detailed instructions based on the worker's state, including port information.
- Introduced `getWorkerRestartInstructions` utility in `error-messages.ts` to generate platform-aware error messages for worker failures.

src/hooks/user-message-hook.ts

@@ -9,6 +9,7 @@
 import { basename } from "path";
 import { ensureWorkerRunning, getWorkerPort } from "../shared/worker-utils.js";
 import { HOOK_EXIT_CODES } from "../shared/hook-constants.js";
+import { getWorkerRestartInstructions } from "../utils/error-messages.js";
 
 try {
   // Ensure worker is running
@@ -24,7 +25,7 @@ try {
   );
 
   if (!response.ok) {
-    throw new Error(`Worker error ${response.status}`);
+    throw new Error(getWorkerRestartInstructions({ includeSkillFallback: true }));
   }
 
   const output = await response.text();