📝 Update .gitignore - Exclude user-generated media and data files

- Added app/static/media/posts/ to exclude user-uploaded GPX files and images
- Added data/ directory to exclude database and runtime data
- Cleaned up temporary backup files
- Ensures repository stays clean while preserving application functionality

.gitignore

@@ -121,3 +121,7 @@ uploads/
 *.sqlite
 instance/
 venv/
+
+# Media files and user content
+app/static/media/posts/
+data/