fix(doctor): improve messaging for detection-only hook managers (bd-par1)

When bd doctor detects hook managers we can't fully check (pre-commit,
overcommit, yorkie, simple-git-hooks), it now shows an informational
message instead of a warning:

  ✓ pre-commit detected (cannot verify bd integration)
    └─ Ensure your hook config calls 'bd hooks run <hook>'

Previously it incorrectly warned that these managers were "not calling bd"
when we simply couldn't verify their config.

Changes:
- Add DetectionOnly field to HookIntegrationStatus
- Set DetectionOnly=true for unsupported managers in CheckExternalHookManagerIntegration
- Update CheckGitHooks and CheckSyncBranchHookCompatibility to show
  informational message for detection-only managers
- Add test coverage for DetectionOnly behavior

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

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

cmd/bd/doctor/fix/hooks.go

@@ -79,6 +79,7 @@ type HookIntegrationStatus struct {
 	HooksWithoutBd   []string // Hooks configured but without bd integration
 	HooksNotInConfig []string // Recommended hooks not in config at all
 	Configured       bool     // Whether any bd integration was found
+	DetectionOnly    bool     // True if we detected the manager but can't verify its config
 }
 
 // bdHookPattern matches the recommended bd hooks run pattern with word boundaries
@@ -330,10 +331,11 @@ func CheckExternalHookManagerIntegration(path string) *HookIntegrationStatus {
 		}
 	}
 
-	// Return basic status for unsupported managers
+	// Return basic status for unsupported managers (detection only, can't verify config)
 	return &HookIntegrationStatus{
-		Manager:    ManagerNames(managers),
-		Configured: false,
+		Manager:       ManagerNames(managers),
+		Configured:    false,
+		DetectionOnly: true,
 	}
 }