Remove Firebase and Vercel deployment options

- Remove firebase package dependency
- Delete apphosting.yaml configuration file
- Update README.md to focus on AWS S3 deployment only
- Update CLAUDE.md documentation accordingly
- Clean up package-lock.json (removed 54 packages)

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.claude/settings.local.json

@@ -17,7 +17,9 @@
       "Bash(git reset:*)",
       "Bash(git checkout:*)",
       "WebFetch(domain:cheatingchelsea.com)",
-      "Bash(npm install:*)"
+      "Bash(npm install:*)",
+      "Bash(npm run typecheck:*)",
+      "Bash(rm:*)"
     ],
     "deny": []
   }