refactor: improve code quality with stricter TypeScript and memory leak prevention

- Add stricter TypeScript compiler flags (noUnusedLocals, noUnusedParameters,
  noImplicitReturns, noImplicitOverride, noFallthroughCasesInSwitch,
  allowUnreachableCode, allowUnusedLabels)
- Remove unused variables caught by stricter flags:
  - Remove unused `renameSession` destructuring in App.tsx
  - Remove unused `BG_GRAY` constant in DirectAttach.ts
  - Remove unused `INPUT_BATCH_INTERVAL` constant in useSessionManager.ts
- Add proper EventEmitter cleanup to RalphLoop:
  - Store bound event handlers for cleanup
  - Add cleanupEventHandlers() method
  - Add destroy() method for complete cleanup
  - Add destroyRalphLoop() singleton cleanup function
- Update ralph-loop tests to use destroy() instead of stop() to prevent
  MaxListenersExceededWarning

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

src/tui/App.tsx

@@ -122,7 +122,6 @@ export function App(): React.ReactElement {
     cases,
     lastUsedCase,
     toggleRespawn,
-    renameSession,
   } = useSessionManager();
 
   // Calculate terminal height based on stdout dimensions

src/tui/DirectAttach.ts

@@ -17,7 +17,6 @@ const RESET = `${CSI}0m`;
 const BOLD = `${CSI}1m`;
 const DIM = `${CSI}2m`;
 const BG_BLUE = `${CSI}44m`;
-const BG_GRAY = `${CSI}48;5;238m`;
 const FG_WHITE = `${CSI}37m`;
 const FG_CYAN = `${CSI}36m`;
 const FG_YELLOW = `${CSI}33m`;

src/tui/hooks/useSessionManager.ts

@@ -37,7 +37,6 @@ const SCREENS_FILE = join(homedir(), '.claudeman', 'screens.json');
 const INNER_STATE_FILE = join(homedir(), '.claudeman', 'state-inner.json');
 const SETTINGS_FILE = join(homedir(), '.claudeman', 'settings.json');
 const OUTPUT_POLL_INTERVAL = 300; // Poll terminal output every 300ms (faster refresh)
-const INPUT_BATCH_INTERVAL = 16; // Batch input every 16ms (60fps)
 
 /**
  * Emoji to ASCII replacement map for screen hardcopy output.