test: add isolated production acceptance harness

reports/architecture-audit.json

@@ -1,5 +1,5 @@
 {
-  "generatedAt": "2026-07-29T16:20:01.552Z",
+  "generatedAt": "2026-07-29T16:52:29.798Z",
   "thresholds": {
     "preferredMaximumLines": 750,
     "justificationRequiredLines": 1000
@@ -283,9 +283,9 @@
     },
     {
       "file": "src/renderer/dialogs.js",
-      "lines": 320,
-      "branches": 34,
-      "functions": 65,
+      "lines": 324,
+      "branches": 35,
+      "functions": 66,
       "ipcHandlers": 0,
       "responsibilities": [
         "inventory",
@@ -295,7 +295,7 @@
         "security",
         "updates"
       ],
-      "hotspotScore": 74
+      "hotspotScore": 75
     },
     {
       "file": "src/main/unraid-access-methods.cjs",
@@ -462,7 +462,7 @@
     },
     {
       "file": "src/renderer/mock-deployment-bridge.js",
-      "lines": 678,
+      "lines": 679,
       "branches": 11,
       "functions": 87,
       "ipcHandlers": 0,
@@ -506,6 +506,21 @@
       ],
       "hotspotScore": 49
     },
+    {
+      "file": "src/main/production-acceptance-harness.cjs",
+      "lines": 152,
+      "branches": 19,
+      "functions": 28,
+      "ipcHandlers": 0,
+      "responsibilities": [
+        "inventory",
+        "deployment",
+        "git",
+        "security",
+        "updates"
+      ],
+      "hotspotScore": 49
+    },
     {
       "file": "src/main/unraid-state-methods.cjs",
       "lines": 283,