security: remove .env file from repository

- Remove .env file from git tracking to prevent exposure of API keys
- Keep .env.example for setup instructions
- Update .gitignore to exclude .env variations

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

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

Author: dino

.env

@@ -1,6 +1,7 @@
 # API keys and secrets
 .env
 .env~
+".env "
 
 # gemini-cli settings
 .gemini/