chore: update .gitignore and remove .env files from tracking

- Add Python cache, test artifacts, backups, models to .gitignore
- Remove .env and .env.development from tracking (security)
- Keep release documentation, ignore binaries

.gitignore

@@ -45,3 +45,48 @@ id_*
 # Frontend dependencies
 node_modules/
 portal/src-tauri/target/
+
+# Python cache
+__pycache__/
+*.pyc
+*.pyo
+
+# Test artifacts
+test_output/
+test_output_simple/
+test_output_v2/
+*.mp4
+*.pt
+server.pid
+server.pid.*
+
+# Backup files
+*.bak
+*.backup
+*.bak[0-9]
+
+# Model files
+models/
+model_checkpoints/
+pretrained_models/
+
+# Desktop app
+momentry_desktop/
+
+# Release artifacts (track docs, ignore binaries)
+release/*.zip
+release/momentry_v*
+release/*.sql
+release/dev_data_*.sql
+release/public_schema_*.sql
+release/migrate_*.sql
+
+# But track release documentation
+!release/*.md
+!release/*.txt
+
+# Data directories
+data/
+
+# System status
+system_status_*.md