Refactor silent debugging to happy path error handling

- Replaced instances of silentDebug with happy_path_error__with_fallback across multiple files to improve error logging and handling.
- Updated the utility function to provide clearer semantics for error handling when expected values are missing.
- Introduced a script to find potential silent failures in the codebase that may need to be addressed with the new error handling approach.

src/hooks/cleanup-hook.ts

@@ -8,7 +8,7 @@
 
 import { stdin } from 'process';
 import { ensureWorkerRunning, getWorkerPort } from '../shared/worker-utils.js';
-import { silentDebug } from '../utils/silent-debug.js';
+import { happy_path_error__with_fallback } from '../utils/silent-debug.js';
 import { HOOK_TIMEOUTS } from '../shared/hook-constants.js';
 
 export interface SessionEndInput {
@@ -26,7 +26,7 @@ async function cleanupHook(input?: SessionEndInput): Promise<void> {
   // Ensure worker is running before any other logic
   await ensureWorkerRunning();
 
-  silentDebug('[cleanup-hook] Hook fired', {
+  happy_path_error__with_fallback('[cleanup-hook] Hook fired', {
     session_id: input?.session_id,
     cwd: input?.cwd,
     reason: input?.reason
@@ -64,14 +64,14 @@ async function cleanupHook(input?: SessionEndInput): Promise<void> {
 
     if (response.ok) {
       const result = await response.json();
-      silentDebug('[cleanup-hook] Session cleanup completed', result);
+      happy_path_error__with_fallback('[cleanup-hook] Session cleanup completed', result);
     } else {
       // Non-fatal - session might not exist
-      silentDebug('[cleanup-hook] Session not found or already cleaned up');
+      happy_path_error__with_fallback('[cleanup-hook] Session not found or already cleaned up');
     }
   } catch (error: any) {
     // Worker might not be running - that's okay
-    silentDebug('[cleanup-hook] Worker not reachable (non-critical)', {
+    happy_path_error__with_fallback('[cleanup-hook] Worker not reachable (non-critical)', {
       error: error.message
     });
   }