DC-005: Fix all 138 broken test paths after src/ refactor

After the DC-005 module reorganization (41 files moved into src/ subdirs),
138 test suites failed because the refactor script's path-rewrite logic
missed three categories:

1. Files inside src/ doing 'require("./src/...")' — should be 'require("../...")'
2. Files in src/X/Y/ doing 'require("../../../src/...")' — should be 'require("../../...")'
3. Test files in __tests__/ with leftover 'require("../../../src/...")' paths

Root cause: the original refactor script ran before all files were moved,
so it computed relative paths against stale filesystem state.

Result:
- 30/30 test suites pass
- 879/879 tests pass (was: 18/30 suites, 614/687 tests)

Also fixed:
- routes/apps/restore.js: wrong responses import path
- routes/*/*.js: '../../src/utilities/X' → '../src/utilities/X' (depth 2 routes)

dashcaddy-api/__tests__/input-validator.test.js

@@ -11,7 +11,7 @@ const {
   isValidPort,
   isPrivateIP,
   validateSecurePath
-} = require('../input-validator');
+} = require('../src/security/input-validator');
 
 describe('Input Validator', () => {
   function fail(message) {
@@ -480,7 +480,7 @@ describe('Input Validator', () => {
 
     // Re-require after mocking fs
     function getValidateSecurePath() {
-      return require('../input-validator').validateSecurePath;
+      return require('../src/security/input-validator').validateSecurePath;
     }
 
     it('resolves valid path within allowed roots', async () => {