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/src/monitoring/metrics.js

@@ -0,0 +1,115 @@
+/**
+ * Simple metrics collector for DashCaddy API
+ * Tracks request counts, durations, errors, and business metrics
+ * No external dependencies — all in-memory
+ */
+
+class Metrics {
+  constructor() {
+    this.startTime = Date.now();
+    this.requests = {
+      total: 0,
+      byStatus: {},
+      byMethod: {},
+      byPath: {}
+    };
+    this.errors = {
+      total: 0,
+      byType: {}
+    };
+    this.business = {
+      containersDeployed: 0,
+      containersDeleted: 0,
+      containerUpdates: 0,
+      dnsRecordsCreated: 0,
+      backupsCreated: 0,
+      totpLogins: 0,
+      siteAdded: 0,
+      siteRemoved: 0,
+      credentialRotations: 0
+    };
+  }
+
+  recordRequest(method, path, statusCode, durationMs) {
+    this.requests.total++;
+    this.requests.byStatus[statusCode] = (this.requests.byStatus[statusCode] || 0) + 1;
+    this.requests.byMethod[method] = (this.requests.byMethod[method] || 0) + 1;
+
+    const normalized = this.normalizePath(path);
+    if (!this.requests.byPath[normalized]) {
+      this.requests.byPath[normalized] = { count: 0, totalDuration: 0 };
+    }
+    const entry = this.requests.byPath[normalized];
+    entry.count++;
+    entry.totalDuration += durationMs;
+  }
+
+  recordError(errorType) {
+    this.errors.total++;
+    this.errors.byType[errorType] = (this.errors.byType[errorType] || 0) + 1;
+  }
+
+  recordBusinessEvent(eventType) {
+    if (eventType in this.business) {
+      this.business[eventType]++;
+    }
+  }
+
+  normalizePath(p) {
+    return p
+      .replace(/\/[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}/gi, '/:id')
+      .replace(/\/[0-9a-f]{12,}/gi, '/:id')
+      .replace(/\/\d+/g, '/:n');
+  }
+
+  getSummary() {
+    const uptimeMs = Date.now() - this.startTime;
+    const uptimeSec = Math.floor(uptimeMs / 1000);
+
+    const topEndpoints = Object.entries(this.requests.byPath)
+      .sort((a, b) => b[1].count - a[1].count)
+      .slice(0, 15)
+      .map(([path, s]) => ({ path, count: s.count, avgMs: Math.round(s.totalDuration / s.count) }));
+
+    return {
+      uptime: { ms: uptimeMs, human: this.formatUptime(uptimeSec) },
+      requests: {
+        total: this.requests.total,
+        perSecond: uptimeSec > 0 ? +(this.requests.total / uptimeSec).toFixed(2) : 0,
+        byStatus: this.requests.byStatus,
+        byMethod: this.requests.byMethod,
+        topEndpoints
+      },
+      errors: {
+        total: this.errors.total,
+        rate: this.requests.total > 0 ? +((this.errors.total / this.requests.total) * 100).toFixed(2) : 0,
+        byType: this.errors.byType
+      },
+      business: this.business,
+      process: {
+        memory: process.memoryUsage(),
+        pid: process.pid,
+        nodeVersion: process.version
+      }
+    };
+  }
+
+  formatUptime(sec) {
+    const d = Math.floor(sec / 86400);
+    const h = Math.floor((sec % 86400) / 3600);
+    const m = Math.floor((sec % 3600) / 60);
+    const s = sec % 60;
+    if (d > 0) return `${d}d ${h}h ${m}m`;
+    if (h > 0) return `${h}h ${m}m ${s}s`;
+    if (m > 0) return `${m}m ${s}s`;
+    return `${s}s`;
+  }
+
+  reset() {
+    this.startTime = Date.now();
+    this.requests = { total: 0, byStatus: {}, byMethod: {}, byPath: {} };
+    this.errors = { total: 0, byType: {} };
+  }
+}
+
+module.exports = new Metrics();