feat: integrate detect-pollution into bd doctor --check=pollution (bd-kff0)

- Add --check flag to doctor for specific check modes
- Add --check=pollution to run detailed pollution detection
- Add --clean flag to delete detected test issues
- Mark detect-pollution command as hidden (deprecated)
- Update fix messages to point to new doctor --check=pollution

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

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

cmd/bd/detect_pollution.go

@@ -12,15 +12,17 @@ import (
 	"github.com/steveyegge/beads/internal/ui"
 )
 
-// showDetectPollutionDeprecationHint shows a hint about bd doctor consolidation (bd-bqcc)
+// showDetectPollutionDeprecationHint shows a hint about bd doctor consolidation (bd-kff0)
 func showDetectPollutionDeprecationHint() {
-	fmt.Fprintln(os.Stderr, ui.RenderMuted("💡 Tip: 'bd doctor' now detects test pollution in the Metadata section"))
+	fmt.Fprintln(os.Stderr, ui.RenderMuted("💡 Tip: Use 'bd doctor --check=pollution' instead (this command is deprecated)"))
 }
 
 var detectPollutionCmd = &cobra.Command{
-	Use:     "detect-pollution",
-	GroupID: "maint",
-	Short:   "Detect and optionally clean test issues from database",
+	Use:        "detect-pollution",
+	GroupID:    "maint",
+	Hidden:     true, // bd-kff0: deprecated, use 'bd doctor --check=pollution' instead
+	Deprecated: "use 'bd doctor --check=pollution' instead",
+	Short:      "Detect and optionally clean test issues from database",
 	Long: `Detect test issues that leaked into production database using pattern matching.
 
 This command finds issues that appear to be test data based on: