Add tests for DC-105/106/108 endpoints + fleet env fix

- Wizard: 6 tests (categories, recommend, hardware profiles, apply)
- Caddycode: 5 tests (generate, validate, templates)
- Fleet: 4 tests (register, list, deploy, validation)
- Fleet: loadHosts/saveHosts now reads env at call time for test isolation
- 1648 tests pass, 72 suites

dashcaddy-api/routes/fleet.js

@@ -28,8 +28,9 @@ module.exports = function({ log, asyncHandler }) {
   const router = express.Router();
 
   async function loadHosts() {
+    const hostsFile = process.env.FLEET_HOSTS_FILE || HOSTS_FILE;
     try {
-      const data = await fsp.readFile(HOSTS_FILE, 'utf8');
+      const data = await fsp.readFile(hostsFile, 'utf8');
       return JSON.parse(data);
     } catch {
       return [];
@@ -37,8 +38,9 @@ module.exports = function({ log, asyncHandler }) {
   }
 
   async function saveHosts(hosts) {
-    await fsp.mkdir(path.dirname(HOSTS_FILE), { recursive: true });
-    await fsp.writeFile(HOSTS_FILE, JSON.stringify(hosts, null, 2));
+    const hostsFile = process.env.FLEET_HOSTS_FILE || HOSTS_FILE;
+    await fsp.mkdir(path.dirname(hostsFile), { recursive: true });
+    await fsp.writeFile(hostsFile, JSON.stringify(hosts, null, 2));
   }
 
   // GET /api/v1/fleet/hosts