refactor: integrate secure file system operations across services

This commit replaces direct file system operations with a secure file system adapter to enhance security by enforcing path validation. The changes include:

- Replaced `fs` imports with `secureFs` in various services and utilities.
- Updated file operations in `agent-service`, `auto-mode-service`, `feature-loader`, and `settings-service` to use the secure file system methods.
- Ensured that all file I/O operations are validated against the ALLOWED_ROOT_DIRECTORY.

This refactor aims to prevent unauthorized file access and improve overall security posture.

Tests: All unit tests passing.

🤖 Generated with Claude Code

apps/server/src/routes/features/routes/create.ts

@@ -7,7 +7,6 @@ import {
   FeatureLoader,
   type Feature,
 } from "../../../services/feature-loader.js";
-import { validatePath, PathNotAllowedError } from "../../../lib/security.js";
 import { getErrorMessage, logError } from "../common.js";
 
 export function createCreateHandler(featureLoader: FeatureLoader) {
@@ -28,20 +27,6 @@ export function createCreateHandler(featureLoader: FeatureLoader) {
         return;
       }
 
-      // Validate path is within ALLOWED_ROOT_DIRECTORY
-      try {
-        validatePath(projectPath);
-      } catch (error) {
-        if (error instanceof PathNotAllowedError) {
-          res.status(403).json({
-            success: false,
-            error: error.message,
-          });
-          return;
-        }
-        throw error;
-      }
-
       const created = await featureLoader.create(projectPath, feature);
       res.json({ success: true, feature: created });
     } catch (error) {