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);

src/utils/frontmatter-utils.ts

@@ -1,5 +1,16 @@
 import { parseYaml } from 'obsidian';
 
+/**
+ * YAML value types that can appear in frontmatter
+ */
+export type YAMLValue =
+	| string
+	| number
+	| boolean
+	| null
+	| YAMLValue[]
+	| { [key: string]: YAMLValue };
+
 /**
  * Utility class for parsing and extracting frontmatter from markdown files
  */
@@ -11,7 +22,7 @@ export class FrontmatterUtils {
 	static extractFrontmatter(content: string): {
 		hasFrontmatter: boolean;
 		frontmatter: string;
-		parsedFrontmatter: Record<string, any> | null;
+		parsedFrontmatter: Record<string, YAMLValue> | null;
 		content: string;
 		contentWithoutFrontmatter: string;
 	} {
@@ -59,7 +70,7 @@ export class FrontmatterUtils {
 		const contentWithoutFrontmatter = contentLines.join('\n');
 
 		// Parse YAML using Obsidian's built-in parser
-		let parsedFrontmatter: Record<string, any> | null = null;
+		let parsedFrontmatter: Record<string, YAMLValue> | null = null;
 		try {
 			parsedFrontmatter = parseYaml(frontmatter) || {};
 		} catch (error) {
@@ -80,17 +91,17 @@ export class FrontmatterUtils {
 	 * Extract only the frontmatter summary (common fields)
 	 * Useful for list operations without reading full content
 	 */
-	static extractFrontmatterSummary(parsedFrontmatter: Record<string, any> | null): {
+	static extractFrontmatterSummary(parsedFrontmatter: Record<string, YAMLValue> | null): {
 		title?: string;
 		tags?: string[];
 		aliases?: string[];
-		[key: string]: any;
+		[key: string]: YAMLValue | undefined;
 	} | null {
 		if (!parsedFrontmatter) {
 			return null;
 		}
 
-		const summary: Record<string, any> = {};
+		const summary: Record<string, YAMLValue> = {};
 
 		// Extract common fields
 		if (parsedFrontmatter.title) {
@@ -136,7 +147,7 @@ export class FrontmatterUtils {
 	 * Serialize frontmatter object to YAML string with delimiters
 	 * Returns the complete frontmatter block including --- delimiters
 	 */
-	static serializeFrontmatter(data: Record<string, any>): string {
+	static serializeFrontmatter(data: Record<string, YAMLValue>): string {
 		if (!data || Object.keys(data).length === 0) {
 			return '';
 		}
@@ -203,7 +214,7 @@ export class FrontmatterUtils {
 		isExcalidraw: boolean;
 		elementCount?: number;
 		hasCompressedData?: boolean;
-		metadata?: Record<string, any>;
+		metadata?: Record<string, YAMLValue>;
 	} {
 		try {
 			// Excalidraw files are typically markdown with a code block containing JSON
@@ -287,7 +298,7 @@ export class FrontmatterUtils {
 
 			// Check if data is compressed (base64 encoded)
 			const trimmedJson = jsonString.trim();
-			let jsonData: any;
+			let jsonData: Record<string, YAMLValue>;
 			
 			if (trimmedJson.startsWith('N4KAk') || !trimmedJson.startsWith('{')) {
 				// Data is compressed - try to decompress
@@ -328,9 +339,9 @@ export class FrontmatterUtils {
 			
 			// Parse the JSON (uncompressed format)
 			jsonData = JSON.parse(trimmedJson);
-			
+
 			// Count elements
-			const elementCount = jsonData.elements ? jsonData.elements.length : 0;
+			const elementCount = Array.isArray(jsonData.elements) ? jsonData.elements.length : 0;
 			
 			// Check for compressed data (files or images)
 			const hasCompressedData = !!(jsonData.files && Object.keys(jsonData.files).length > 0);