Refactor hooks codebase: reduce complexity and improve maintainability (#204)

* refactor: Clean up hook-response and new-hook files

- Removed 'PreCompact' hook type and associated logic from hook-response.ts for improved type safety.
- Deleted extensive architecture comments in new-hook.ts to streamline code readability.
- Simplified debug logging in new-hook.ts to reduce verbosity.
- Enhanced ensureWorkerRunning function in worker-utils.ts with a final health check before throwing errors.
- Added a new documentation file outlining the hooks cleanup process and future improvements.

* Refactor cleanup and user message hooks

- Updated cleanup-hook.js to improve error handling and remove unnecessary input checks.
- Simplified user-message-hook.js by removing time-sensitive announcements and streamlining output.
- Enhanced logging functionality in both hooks for better debugging and clarity.

* Refactor error handling in hooks to use centralized error handler

- Introduced `handleWorkerError` function in `src/shared/hook-error-handler.ts` to manage worker-related errors.
- Updated `context-hook.ts`, `new-hook.ts`, `save-hook.ts`, and `summary-hook.ts` to utilize the new error handler, simplifying error management and improving code readability.
- Removed repetitive error handling logic from individual hooks, ensuring consistent user-friendly messages for connection issues.

* Refactor user-message and summary hooks to utilize shared transcript parser; introduce hook exit codes

- Moved user message extraction logic to a new shared module `transcript-parser.ts` for better code reuse.
- Updated `summary-hook.ts` to use the new `extractLastMessage` function for retrieving user and assistant messages.
- Replaced direct exit code usage in `user-message-hook.ts` with constants from `hook-constants.ts` for improved readability and maintainability.
- Added `HOOK_EXIT_CODES` to `hook-constants.ts` to standardize exit codes across hooks.

* Refactor hook input interfaces to enforce required fields

- Updated `SessionStartInput`, `UserPromptSubmitInput`, `PostToolUseInput`, and `StopInput` interfaces to require `session_id`, `transcript_path`, and `cwd` fields, ensuring better type safety and clarity in hook inputs.
- Removed optional index signatures from these interfaces to prevent unintended properties and improve code maintainability.
- Adjusted related hook implementations to align with the new interface definitions.

* Refactor save-hook to remove tool skipping logic; enhance summary-hook to handle spinner stopping with error logging; update SessionRoutes to load skip tools from settings; add CLAUDE_MEM_SKIP_TOOLS to SettingsDefaultsManager for configurable tool exclusion.

* Document CLAUDE_MEM_SKIP_TOOLS setting in public docs

Added documentation for the new CLAUDE_MEM_SKIP_TOOLS configuration
setting in response to PR review feedback. Users can now discover and
customize which tools are excluded from observations.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>

src/hooks/cleanup-hook.ts

@@ -13,9 +13,6 @@ import { HOOK_TIMEOUTS } from '../shared/hook-constants.js';
 
 export interface SessionEndInput {
   session_id: string;
-  cwd: string;
-  transcript_path?: string;
-  hook_event_name: string;
   reason: 'exit' | 'clear' | 'logout' | 'prompt_input_exit' | 'other';
 }
 
@@ -28,22 +25,11 @@ async function cleanupHook(input?: SessionEndInput): Promise<void> {
 
   happy_path_error__with_fallback('[cleanup-hook] Hook fired', {
     session_id: input?.session_id,
-    cwd: input?.cwd,
     reason: input?.reason
   });
 
-  // Handle standalone execution (no input provided)
   if (!input) {
-    console.log('No input provided - this script is designed to run as a Claude Code SessionEnd hook');
-    console.log('\nExpected input format:');
-    console.log(JSON.stringify({
-      session_id: "string",
-      cwd: "string",
-      transcript_path: "string",
-      hook_event_name: "SessionEnd",
-      reason: "exit"
-    }, null, 2));
-    process.exit(0);
+    throw new Error('cleanup-hook requires input from Claude Code');
   }
 
   const { session_id, reason } = input;