feat(convoy): add specific convoy ID check and dry-run flag

Add support for checking a specific convoy by ID instead of all convoys:
- `gt convoy check <convoy-id>` - check specific convoy
- `gt convoy check` - check all (existing behavior)
- `gt convoy check --dry-run` - preview mode

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

internal/cmd/convoy.go

@@ -73,6 +73,7 @@ var (
 	convoyStrandedJSON bool
 	convoyCloseReason  string
 	convoyCloseNotify  string
+	convoyCheckDryRun  bool
 )
 
 var convoyCmd = &cobra.Command{
@@ -177,14 +178,22 @@ Examples:
 }
 
 var convoyCheckCmd = &cobra.Command{
-	Use:   "check",
+	Use:   "check [convoy-id]",
 	Short: "Check and auto-close completed convoys",
-	Long: `Check all open convoys and auto-close any where all tracked issues are complete.
+	Long: `Check convoys and auto-close any where all tracked issues are complete.
+
+Without arguments, checks all open convoys. With a convoy ID, checks only that convoy.
 
 This handles cross-rig convoy completion: convoys in town beads tracking issues
 in rig beads won't auto-close via bd close alone. This command bridges that gap.
 
-Can be run manually or by deacon patrol to ensure convoys close promptly.`,
+Can be run manually or by deacon patrol to ensure convoys close promptly.
+
+Examples:
+  gt convoy check              # Check all open convoys
+  gt convoy check hq-cv-abc    # Check specific convoy
+  gt convoy check --dry-run    # Preview what would close without acting`,
+	Args: cobra.MaximumNArgs(1),
 	RunE: runConvoyCheck,
 }
 
@@ -248,6 +257,9 @@ func init() {
 	// Interactive TUI flag (on parent command)
 	convoyCmd.Flags().BoolVarP(&convoyInteractive, "interactive", "i", false, "Interactive tree view")
 
+	// Check flags
+	convoyCheckCmd.Flags().BoolVar(&convoyCheckDryRun, "dry-run", false, "Preview what would close without acting")
+
 	// Stranded flags
 	convoyStrandedCmd.Flags().BoolVar(&convoyStrandedJSON, "json", false, "Output as JSON")
 
@@ -478,15 +490,26 @@ func runConvoyCheck(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
-	closed, err := checkAndCloseCompletedConvoys(townBeads)
+	// If a specific convoy ID is provided, check only that convoy
+	if len(args) == 1 {
+		convoyID := args[0]
+		return checkSingleConvoy(townBeads, convoyID, convoyCheckDryRun)
+	}
+
+	// Check all open convoys
+	closed, err := checkAndCloseCompletedConvoys(townBeads, convoyCheckDryRun)
 	if err != nil {
 		return err
 	}
 
 	if len(closed) == 0 {
 		fmt.Println("No convoys ready to close.")
+	} else {
+		if convoyCheckDryRun {
+			fmt.Printf("%s Would auto-close %d convoy(s):\n", style.Warning.Render("⚠"), len(closed))
 		} else {
 			fmt.Printf("%s Auto-closed %d convoy(s):\n", style.Bold.Render("✓"), len(closed))
+		}
 		for _, c := range closed {
 			fmt.Printf("  🚚 %s: %s\n", c.ID, c.Title)
 		}
@@ -495,6 +518,92 @@ func runConvoyCheck(cmd *cobra.Command, args []string) error {
 	return nil
 }
 
+// checkSingleConvoy checks a specific convoy and closes it if all tracked issues are complete.
+func checkSingleConvoy(townBeads, convoyID string, dryRun bool) error {
+	// Get convoy details
+	showArgs := []string{"show", convoyID, "--json"}
+	showCmd := exec.Command("bd", showArgs...)
+	showCmd.Dir = townBeads
+	var stdout bytes.Buffer
+	showCmd.Stdout = &stdout
+
+	if err := showCmd.Run(); err != nil {
+		return fmt.Errorf("convoy '%s' not found", convoyID)
+	}
+
+	var convoys []struct {
+		ID          string `json:"id"`
+		Title       string `json:"title"`
+		Status      string `json:"status"`
+		Type        string `json:"issue_type"`
+		Description string `json:"description"`
+	}
+	if err := json.Unmarshal(stdout.Bytes(), &convoys); err != nil {
+		return fmt.Errorf("parsing convoy data: %w", err)
+	}
+
+	if len(convoys) == 0 {
+		return fmt.Errorf("convoy '%s' not found", convoyID)
+	}
+
+	convoy := convoys[0]
+
+	// Verify it's actually a convoy type
+	if convoy.Type != "convoy" {
+		return fmt.Errorf("'%s' is not a convoy (type: %s)", convoyID, convoy.Type)
+	}
+
+	// Check if convoy is already closed
+	if convoy.Status == "closed" {
+		fmt.Printf("%s Convoy %s is already closed\n", style.Dim.Render("○"), convoyID)
+		return nil
+	}
+
+	// Get tracked issues
+	tracked := getTrackedIssues(townBeads, convoyID)
+	if len(tracked) == 0 {
+		fmt.Printf("%s Convoy %s has no tracked issues\n", style.Dim.Render("○"), convoyID)
+		return nil
+	}
+
+	// Check if all tracked issues are closed
+	allClosed := true
+	openCount := 0
+	for _, t := range tracked {
+		if t.Status != "closed" && t.Status != "tombstone" {
+			allClosed = false
+			openCount++
+		}
+	}
+
+	if !allClosed {
+		fmt.Printf("%s Convoy %s has %d open issue(s) remaining\n", style.Dim.Render("○"), convoyID, openCount)
+		return nil
+	}
+
+	// All tracked issues are complete - close the convoy
+	if dryRun {
+		fmt.Printf("%s Would auto-close convoy 🚚 %s: %s\n", style.Warning.Render("⚠"), convoyID, convoy.Title)
+		return nil
+	}
+
+	// Actually close the convoy
+	closeArgs := []string{"close", convoyID, "-r", "All tracked issues completed"}
+	closeCmd := exec.Command("bd", closeArgs...)
+	closeCmd.Dir = townBeads
+
+	if err := closeCmd.Run(); err != nil {
+		return fmt.Errorf("closing convoy: %w", err)
+	}
+
+	fmt.Printf("%s Auto-closed convoy 🚚 %s: %s\n", style.Bold.Render("✓"), convoyID, convoy.Title)
+
+	// Send completion notification
+	notifyConvoyCompletion(townBeads, convoyID, convoy.Title)
+
+	return nil
+}
+
 func runConvoyClose(cmd *cobra.Command, args []string) error {
 	convoyID := args[0]
 
@@ -761,8 +870,9 @@ func isReadyIssue(t trackedIssueInfo, blockedIssues map[string]bool) bool {
 }
 
 // checkAndCloseCompletedConvoys finds open convoys where all tracked issues are closed
-// and auto-closes them. Returns the list of convoys that were closed.
+// and auto-closes them. Returns the list of convoys that were closed (or would be closed in dry-run mode).
-func checkAndCloseCompletedConvoys(townBeads string) ([]struct{ ID, Title string }, error) {
+// If dryRun is true, no changes are made and the function returns what would have been closed.
+func checkAndCloseCompletedConvoys(townBeads string, dryRun bool) ([]struct{ ID, Title string }, error) {
 	var closed []struct{ ID, Title string }
 
 	// List all open convoys
@@ -801,6 +911,12 @@ func checkAndCloseCompletedConvoys(townBeads string) ([]struct{ ID, Title string
 		}
 
 		if allClosed {
+			if dryRun {
+				// In dry-run mode, just record what would be closed
+				closed = append(closed, struct{ ID, Title string }{convoy.ID, convoy.Title})
+				continue
+			}
+
 			// Close the convoy
 			closeArgs := []string{"close", convoy.ID, "-r", "All tracked issues completed"}
 			closeCmd := exec.Command("bd", closeArgs...)