Update development environment and ignore files

- Added more directories to `.cursorignore` to exclude temporary and log files
- Updated TODO.md with a new task for downloading E621 user favorites
- Modified Dockerfile.devcontainer to install PostgreSQL 17 client
- Updated VS Code extensions script to add Docker extension
- Added Dockerfile formatter in VS Code settings
- Configured Cursor as the default Git editor in the development container

.cursorignore

@@ -1,3 +1,7 @@
 # Add directories or file patterns to ignore during indexing (e.g. foo/ or *.csv)
 config/database.yml
 config/cookies/fa.yml
+tmp
+log
+public
+.bundle