fix: resolve golangci-lint errors (errcheck, gosec, unparam)

- orphans.go: check fmt.Scanln return value
- edit.go: #nosec G204 for trusted $EDITOR execution
- sync_git.go: #nosec G204 for git commands with internal branch names
- worktree_cmd.go: #nosec G304/G306 for .gitignore file operations
- migrations: handle rows.Close() error
- doctor_pollution.go: mark unused path parameter

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cmd/bd/doctor_pollution.go

@@ -11,7 +11,7 @@ import (
 
 // runPollutionCheck runs detailed test pollution detection
 // This integrates the detect-pollution command functionality into doctor.
-func runPollutionCheck(path string, clean bool, yes bool) {
+func runPollutionCheck(_ string, clean bool, yes bool) {
 	// Ensure we have a store initialized (uses direct mode, no daemon support yet)
 	if err := ensureDirectMode("pollution check requires direct mode"); err != nil {
 		fmt.Fprintf(os.Stderr, "Error: %v\n", err)