fix: replace any types with proper TypeScript types

Replace all `any` types with properly defined TypeScript interfaces and types throughout the codebase to improve type safety and eliminate type-related code quality issues.

Changes:
- Define ElectronSafeStorage interface for Electron's safeStorage API
- Create LegacySettings interface for settings migration in main.ts
- Define JSONValue, JSONRPCParams types for JSON-RPC protocol
- Define JSONSchemaProperty for tool input schemas
- Create YAMLValue type for frontmatter values
- Define FrontmatterValue type for adapter interfaces
- Update middleware to use proper Express NextFunction and JSONRPCResponse types
- Fix tool registry to handle args with proper typing (with eslint-disable for dynamic dispatch)
- Fix notifications to use proper types with eslint-disable where dynamic access is needed
- Add proper null safety assertions where appropriate
- Fix TFolder stat access with proper type extension

All type errors resolved. TypeScript compilation passes with --skipLibCheck.

src/main.ts

@@ -24,7 +24,11 @@ export default class MCPServerPlugin extends Plugin {
 		}
 
 		// Migrate legacy settings (remove enableCORS and allowedOrigins)
-		const legacySettings = this.settings as any;
+		interface LegacySettings extends MCPPluginSettings {
+			enableCORS?: boolean;
+			allowedOrigins?: string[];
+		}
+		const legacySettings = this.settings as LegacySettings;
 		if ('enableCORS' in legacySettings || 'allowedOrigins' in legacySettings) {
 			console.log('Migrating legacy CORS settings...');
 			delete legacySettings.enableCORS;