Refine repository structure

- Update .gitignore for dev/ and tmp/ directories
- Move certificate setup to dev/ directory with README
- Remove production references from AGENTS.md
- Clean up directory structure and documentation
- Repository now ready for development workflow

.gitignore

@@ -1,22 +1,24 @@
-# Rust build artifacts
-/target/
-Cargo.lock
+# Development directories
+dev/
+tmp/
+test_files/
+sample_data/
 
-# Development files
+# Temporary files
 *.log
-*.md.tmp
-
-# OS files
+*.tmp
 .DS_Store
-Thumbs.db
 
 # TLS certificates - NEVER commit to repository
 *.pem
 *.key
 *.crt
-certs/
 certbot/
 
+# Rust build artifacts
+/target/
+Cargo.lock
+
 # IDE files
 .vscode/
 .idea/