SECURITY: Remove .env from Git tracking and add to .gitignore

- Remove sensitive .env file from Git repository
- Add comprehensive .env file patterns to .gitignore
- Prevent accidental commit of environment variables and secrets

.gitignore

@@ -3,6 +3,10 @@ ACCOUNTS.txt
 *.key
 *.pem
 *.p12
+.env
+app/.env
+*.env.local
+*.env.production
 
 # Python
 __pycache__/