fix: prevent closing issues with open blockers (GH#962)

Added IsBlocked method to Storage interface that checks if an issue is
in the blocked_issues_cache and returns the blocking issue IDs.

The close command now checks for blockers before allowing an issue to
be closed:
- If an issue has open blockers, closing is blocked with an error message
- The --force flag overrides this check
- Works in both daemon mode (RPC) and direct storage mode
- Also handles cross-rig routed IDs

This addresses the bug where agents could close a bead even when it
depends on an open bug/issue.

Closes #962

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

cmd/bd/close.go

@@ -122,6 +122,7 @@ create, update, show, or close operation).`,
 					Reason:      reason,
 					Session:     session,
 					SuggestNext: suggestNext,
+					Force:       force,
 				}
 				resp, err := daemonClient.CloseIssue(closeArgs)
 				if err != nil {
@@ -191,6 +192,21 @@ create, update, show, or close operation).`,
 					continue
 				}
 
+				// Check if issue has open blockers (GH#962)
+				if !force {
+					blocked, blockers, err := result.Store.IsBlocked(ctx, result.ResolvedID)
+					if err != nil {
+						result.Close()
+						fmt.Fprintf(os.Stderr, "Error checking blockers for %s: %v\n", id, err)
+						continue
+					}
+					if blocked && len(blockers) > 0 {
+						result.Close()
+						fmt.Fprintf(os.Stderr, "cannot close %s: blocked by open issues %v (use --force to override)\n", id, blockers)
+						continue
+					}
+				}
+
 				if err := result.Store.CloseIssue(ctx, result.ResolvedID, reason, actor, session); err != nil {
 					result.Close()
 					fmt.Fprintf(os.Stderr, "Error closing %s: %v\n", id, err)
@@ -240,6 +256,19 @@ create, update, show, or close operation).`,
 				continue
 			}
 
+			// Check if issue has open blockers (GH#962)
+			if !force {
+				blocked, blockers, err := store.IsBlocked(ctx, id)
+				if err != nil {
+					fmt.Fprintf(os.Stderr, "Error checking blockers for %s: %v\n", id, err)
+					continue
+				}
+				if blocked && len(blockers) > 0 {
+					fmt.Fprintf(os.Stderr, "cannot close %s: blocked by open issues %v (use --force to override)\n", id, blockers)
+					continue
+				}
+			}
+
 			if err := store.CloseIssue(ctx, id, reason, actor, session); err != nil {
 				fmt.Fprintf(os.Stderr, "Error closing %s: %v\n", id, err)
 				continue
@@ -283,6 +312,21 @@ create, update, show, or close operation).`,
 				continue
 			}
 
+			// Check if issue has open blockers (GH#962)
+			if !force {
+				blocked, blockers, err := result.Store.IsBlocked(ctx, result.ResolvedID)
+				if err != nil {
+					result.Close()
+					fmt.Fprintf(os.Stderr, "Error checking blockers for %s: %v\n", id, err)
+					continue
+				}
+				if blocked && len(blockers) > 0 {
+					result.Close()
+					fmt.Fprintf(os.Stderr, "cannot close %s: blocked by open issues %v (use --force to override)\n", id, blockers)
+					continue
+				}
+			}
+
 			if err := result.Store.CloseIssue(ctx, result.ResolvedID, reason, actor, session); err != nil {
 				result.Close()
 				fmt.Fprintf(os.Stderr, "Error closing %s: %v\n", id, err)