chore: ignore backup/temp artifacts and local worktree scratch

.gitignore

@@ -48,6 +48,14 @@ temp_upload/
 *.tmp
 *.temp
 .cache/
+.worktrees/
+*.bak_*
+*.md.bak_*
+*.sh.bak_*
+*.py.bak_*
+*.txt.bak_*
+*.yml.bak_*
+docs_backup_*.tar.gz
 
 # NATS data
 nats-data/