Initial commit: AutoTrader Marker Firefox extension

Mark AutoTrader listings as 'not wanted' on both search results and detail
pages. Includes the unlisted signing / auto-update pipeline (web-ext +
dist/updates.json polled by Firefox).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

manifest.json

@@ -0,0 +1,39 @@
+{
+  "manifest_version": 3,
+  "name": "AutoTrader Marker",
+  "version": "0.1.0",
+  "description": "Mark AutoTrader listings as 'not wanted' so you can spot the ones you haven't reviewed yet.",
+  "permissions": ["storage"],
+  "host_permissions": [
+    "*://*.autotrader.co.uk/*"
+  ],
+  "content_scripts": [
+    {
+      "matches": ["*://*.autotrader.co.uk/*"],
+      "js": ["content.js"],
+      "css": ["content.css"],
+      "run_at": "document_idle",
+      "all_frames": false
+    }
+  ],
+  "action": {
+    "default_title": "AutoTrader Marker",
+    "default_popup": "popup.html",
+    "default_icon": "icon.svg"
+  },
+  "icons": {
+    "48": "icon.svg",
+    "96": "icon.svg",
+    "128": "icon.svg"
+  },
+  "browser_specific_settings": {
+    "gecko": {
+      "id": "autotrader-marker@tony.codes",
+      "strict_min_version": "115.0",
+      "update_url": "https://git.nocker.cloud/tony/autotrader-marker/raw/branch/main/dist/updates.json",
+      "data_collection_permissions": {
+        "required": ["none"]
+      }
+    }
+  }
+}