feat(create): add --dry-run flag to preview issue creation (bd-0hi7)

Adds --dry-run flag that shows what would be created without actually
creating the issue. Useful for scripting and validation.

- Shows preview in human-readable format by default
- Outputs full issue JSON with --json flag (empty ID, not placeholder string)
- Skips all side effects (hooks, labels, dependencies)
- Works with --rig/--prefix flags (shows target rig)
- Errors gracefully with --file flag (not supported)
- Includes event fields when --type=event

cmd/bd/create.go

@@ -36,6 +36,11 @@ var createCmd = &cobra.Command{
 			if len(args) > 0 {
 				FatalError("cannot specify both title and --file flag")
 			}
+			// --dry-run not supported with --file (would need to parse and preview multiple issues)
+			dryRun, _ := cmd.Flags().GetBool("dry-run")
+			if dryRun {
+				FatalError("--dry-run is not supported with --file flag")
+			}
 			createIssuesFromMarkdown(cmd, file)
 			return
 		}
@@ -173,6 +178,81 @@ var createCmd = &cobra.Command{
 			deferUntil = &t
 		}
 
+		// Handle --dry-run flag (before --rig to ensure it works with cross-rig creation)
+		dryRun, _ := cmd.Flags().GetBool("dry-run")
+		if dryRun {
+			// Build preview issue
+			var externalRefPtr *string
+			if externalRef != "" {
+				externalRefPtr = &externalRef
+			}
+			previewIssue := &types.Issue{
+				Title:              title,
+				Description:        description,
+				Design:             design,
+				AcceptanceCriteria: acceptance,
+				Notes:              notes,
+				Status:             types.StatusOpen,
+				Priority:           priority,
+				IssueType:          types.IssueType(issueType),
+				Assignee:           assignee,
+				ExternalRef:        externalRefPtr,
+				Ephemeral:          wisp,
+				CreatedBy:          getActorWithGit(),
+				MolType:            molType,
+				RoleType:           roleType,
+				Rig:                agentRig,
+				DueAt:              dueAt,
+				DeferUntil:         deferUntil,
+				// Event fields
+				EventKind: eventCategory,
+				Actor:     eventActor,
+				Target:    eventTarget,
+				Payload:   eventPayload,
+			}
+			if explicitID != "" {
+				previewIssue.ID = explicitID
+			}
+
+			if jsonOutput {
+				outputJSON(previewIssue)
+			} else {
+				idDisplay := previewIssue.ID
+				if idDisplay == "" {
+					idDisplay = "(will be generated)"
+				}
+				fmt.Printf("%s [DRY RUN] Would create issue:\n", ui.RenderWarn("⚠"))
+				fmt.Printf("  ID: %s\n", idDisplay)
+				fmt.Printf("  Title: %s\n", previewIssue.Title)
+				fmt.Printf("  Type: %s\n", previewIssue.IssueType)
+				fmt.Printf("  Priority: P%d\n", previewIssue.Priority)
+				fmt.Printf("  Status: %s\n", previewIssue.Status)
+				if previewIssue.Assignee != "" {
+					fmt.Printf("  Assignee: %s\n", previewIssue.Assignee)
+				}
+				if previewIssue.Description != "" {
+					fmt.Printf("  Description: %s\n", previewIssue.Description)
+				}
+				if len(labels) > 0 {
+					fmt.Printf("  Labels: %s\n", strings.Join(labels, ", "))
+				}
+				if len(deps) > 0 {
+					fmt.Printf("  Dependencies: %s\n", strings.Join(deps, ", "))
+				}
+				if rigOverride != "" || prefixOverride != "" {
+					rig := rigOverride
+					if rig == "" {
+						rig = prefixOverride
+					}
+					fmt.Printf("  Target rig: %s\n", rig)
+				}
+				if eventCategory != "" {
+					fmt.Printf("  Event category: %s\n", eventCategory)
+				}
+			}
+			return
+		}
+
 		// Handle --rig or --prefix flag: create issue in a different rig
 		// Both flags use the same forgiving lookup (accepts rig names or prefixes)
 		targetRig := rigOverride
@@ -602,6 +682,7 @@ func init() {
 	createCmd.Flags().StringP("file", "f", "", "Create multiple issues from markdown file")
 	createCmd.Flags().String("title", "", "Issue title (alternative to positional argument)")
 	createCmd.Flags().Bool("silent", false, "Output only the issue ID (for scripting)")
+	createCmd.Flags().Bool("dry-run", false, "Preview what would be created without actually creating")
 	registerPriorityFlag(createCmd, "2")
 	createCmd.Flags().StringP("type", "t", "task", "Issue type (bug|feature|task|epic|chore|merge-request|molecule|gate|agent|role|rig|convoy|event)")
 	registerCommonIssueFlags(createCmd)