clean-up few things

* remove un-used files like readabilty

* posthog key to ENV

* update sample env

* dropped v2 prefix

* fix build

* fix package.json files

Author: shadowfax92

.env.example

@@ -1,3 +1,2 @@
-ANTHROPIC_API_KEY=""
-OPENAI_API_KEY=""
-GEMINI_API_KEY=""
+LITELLM_API_KEY=""
+POSTHOG_API_KEY=""

manifest.json

@@ -43,7 +43,7 @@
   "content_scripts": [
     {
       "matches": ["<all_urls>"],
-      "js": ["buildDomTree.js", "content.js"],
+      "js": ["content.js"],
       "run_at": "document_start",
       "all_frames": true
     }