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/utils/encryption-utils.ts

@@ -1,5 +1,12 @@
+// Define Electron SafeStorage interface
+interface ElectronSafeStorage {
+	isEncryptionAvailable(): boolean;
+	encryptString(plainText: string): Buffer;
+	decryptString(encrypted: Buffer): string;
+}
+
 // Safely import safeStorage - may not be available in all environments
-let safeStorage: any = null;
+let safeStorage: ElectronSafeStorage | null = null;
 try {
 	const electron = require('electron');
 	safeStorage = electron.safeStorage || null;
@@ -35,7 +42,7 @@ export function encryptApiKey(apiKey: string): string {
 	}
 
 	try {
-		const encrypted = safeStorage.encryptString(apiKey);
+		const encrypted = safeStorage!.encryptString(apiKey);
 		return `encrypted:${encrypted.toString('base64')}`;
 	} catch (error) {
 		console.error('Failed to encrypt API key, falling back to plaintext:', error);