refactor: remove unused statistics types and methods

Remove unused AppStats, DraftStats interfaces and getAppStats method to clean up codebase and reduce maintenance overhead.

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

Co-Authored-By: Claude <[email protected]>

Author: nkmr-jp

src/handlers/CLAUDE.md

@@ -56,15 +56,13 @@ import {
 - **`remove-history-item`**: Removes specific item with ID format validation
   - Regex validation: `/^[a-z0-9]+$/` (coupled with utils.generateId())
 - **`search-history`**: Full-text search with configurable result limits
-- **`get-history-stats`**: Returns HistoryStats object with metadata
 
 ### Draft Management
 - **`save-draft`**: Draft persistence with debouncing control
   - Supports immediate mode for explicit saves
   - Uses DraftManager's debounced or immediate save methods
 - **`clear-draft`**: Explicit draft removal
 - **`get-draft`**: Current draft content retrieval
-- **`get-draft-stats`**: Draft metadata and statistics
 
 ### Window Management
 - **`show-window`**: Window display with optional WindowData context

src/main.ts

@@ -23,7 +23,7 @@ import DraftManager from './managers/draft-manager';
 import SettingsManager from './managers/settings-manager';
 import IPCHandlers from './handlers/ipc-handlers';
 import { logger, ensureDir } from './utils/utils';
-import type { AppStats, HistoryStats, WindowData, DraftStats } from './types';
+import type { WindowData } from './types';
 
 class PromptLineApp {
   private windowManager: WindowManager | null = null;
@@ -318,31 +318,6 @@ class PromptLineApp {
     }
   }
 
-  getAppStats(): AppStats {
-    const defaultDraftStats: DraftStats = {
-      hasData: false,
-      length: 0,
-      lastSaved: null,
-      autoSaveEnabled: false
-    };
-
-    const draftStats = this.draftManager ? this.draftManager.getDraftStats() : defaultDraftStats;
-    
-    return {
-      isInitialized: this.isInitialized,
-      historyStats: this.historyManager ? this.historyManager.getHistoryStats() : {} as HistoryStats,
-      draftStats: {
-        hasData: 'hasContent' in draftStats ? draftStats.hasContent || false : false,
-        length: draftStats.length || 0,
-        lastSaved: null,
-        autoSaveEnabled: false
-      },
-      windowVisible: this.windowManager ? this.windowManager.isVisible() : false,
-      platform: process.platform,
-      version: config.app.version
-    };
-  }
-
   private async cleanup(): Promise<void> {
     try {
       logger.info('Cleaning up application resources...');

src/types/index.ts

@@ -46,22 +46,6 @@ export interface HistoryStats {
   newestTimestamp: number | null;
 }
 
-export interface DraftStats {
-  hasData: boolean;
-  length: number;
-  lastSaved: number | null;
-  autoSaveEnabled: boolean;
-}
-
-export interface AppStats {
-  isInitialized: boolean;
-  historyStats: HistoryStats;
-  draftStats: DraftStats;
-  windowVisible: boolean;
-  platform: string;
-  version: string;
-}
-
 export interface PlatformConfig {
   isMac: boolean;
   isWindows: boolean;