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
     });
   }

src/hooks/new-hook.ts

@@ -37,7 +37,7 @@ import path from 'path';
 import { stdin } from 'process';
 import { createHookResponse } from './hook-response.js';
 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';
 
 export interface UserPromptSubmitInput {
   session_id: string;
@@ -61,7 +61,7 @@ async function newHook(input?: UserPromptSubmitInput): Promise<void> {
   const { session_id, cwd, prompt } = input;
 
   // Debug: Log what we received
-  silentDebug('[new-hook] Input received', {
+  happy_path_error__with_fallback('[new-hook] Input received', {
     session_id,
     cwd,
     cwd_type: typeof cwd,
@@ -72,7 +72,7 @@ async function newHook(input?: UserPromptSubmitInput): Promise<void> {
 
   const project = path.basename(cwd);
 
-  silentDebug('[new-hook] Project extracted', {
+  happy_path_error__with_fallback('[new-hook] Project extracted', {
     project,
     project_type: typeof project,
     project_length: project?.length,

src/hooks/save-hook.ts

@@ -11,6 +11,7 @@ import { createHookResponse } from './hook-response.js';
 import { logger } from '../utils/logger.js';
 import { ensureWorkerRunning, getWorkerPort } from '../shared/worker-utils.js';
 import { HOOK_TIMEOUTS } from '../shared/hook-constants.js';
+import { happy_path_error__with_fallback } from '../utils/silent-debug.js';
 
 export interface PostToolUseInput {
   session_id: string;
@@ -66,7 +67,11 @@ async function saveHook(input?: PostToolUseInput): Promise<void> {
         tool_name,
         tool_input,
         tool_response,
-        cwd: cwd || ''
+        cwd: happy_path_error__with_fallback(
+          'Missing cwd in PostToolUse hook input',
+          { session_id, tool_name },
+          cwd || ''
+        )
       }),
       signal: AbortSignal.timeout(HOOK_TIMEOUTS.DEFAULT)
     });

src/hooks/summary-hook.ts

@@ -15,6 +15,7 @@ import { createHookResponse } from './hook-response.js';
 import { logger } from '../utils/logger.js';
 import { ensureWorkerRunning, getWorkerPort } from '../shared/worker-utils.js';
 import { HOOK_TIMEOUTS } from '../shared/hook-constants.js';
+import { happy_path_error__with_fallback } from '../utils/silent-debug.js';
 
 export interface StopInput {
   session_id: string;
@@ -143,8 +144,13 @@ async function summaryHook(input?: StopInput): Promise<void> {
   const port = getWorkerPort();
 
   // Extract last user AND assistant messages from transcript
-  const lastUserMessage = extractLastUserMessage(input.transcript_path || '');
-  const lastAssistantMessage = extractLastAssistantMessage(input.transcript_path || '');
+  const transcriptPath = happy_path_error__with_fallback(
+    'Missing transcript_path in Stop hook input',
+    { session_id },
+    input.transcript_path || ''
+  );
+  const lastUserMessage = extractLastUserMessage(transcriptPath);
+  const lastAssistantMessage = extractLastAssistantMessage(transcriptPath);
 
   logger.dataIn('HOOK', 'Stop: Requesting summary', {
     workerPort: port,