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/tools/vault-tools.ts

@@ -385,8 +385,10 @@ export class VaultTools {
 		// In most cases, this will be 0 for directories
 		let modified = 0;
 		try {
-			if ((folder as any).stat && typeof (folder as any).stat.mtime === 'number') {
-				modified = (folder as any).stat.mtime;
+			// TFolder doesn't officially have stat, but it may exist in practice
+			const folderWithStat = folder as TFolder & { stat?: { mtime?: number } };
+			if (folderWithStat.stat && typeof folderWithStat.stat.mtime === 'number') {
+				modified = folderWithStat.stat.mtime;
 			}
 		} catch (error) {
 			// Silently fail - modified will remain 0