fix(mol): prevent nil pointer dereference in wisp create

GetIssue returns (nil, nil) when an issue is not found, but the code
assumed a non-nil issue when err was nil. Added nil checks before
accessing issue fields.

Fixes crash when running `bd mol wisp create` with nonexistent proto.

Closes: gt-2uzn2

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

cmd/bd/wisp.go

@@ -211,11 +211,16 @@ func runWispCreate(cmd *cobra.Command, args []string) {
 		}
 
 		// Load the proto
+		// Note: GetIssue returns (nil, nil) for not-found, so check both
 		protoIssue, err := store.GetIssue(ctx, protoID)
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "Error loading proto %s: %v\n", protoID, err)
 			os.Exit(1)
 		}
+		if protoIssue == nil {
+			fmt.Fprintf(os.Stderr, "Error: proto not found: %s\n", protoID)
+			os.Exit(1)
+		}
 		if !isProtoIssue(protoIssue) {
 			fmt.Fprintf(os.Stderr, "Error: %s is not a proto (missing '%s' label)\n", protoID, MoleculeLabel)
 			os.Exit(1)
@@ -297,7 +302,8 @@ func isProtoIssue(issue *types.Issue) bool {
 // resolvePartialIDDirect resolves a partial ID directly from store
 func resolvePartialIDDirect(ctx context.Context, partial string) (string, error) {
 	// Try direct lookup first
-	if issue, err := store.GetIssue(ctx, partial); err == nil {
+	// Note: GetIssue returns (nil, nil) for not-found, so check both
+	if issue, err := store.GetIssue(ctx, partial); err == nil && issue != nil {
 		return issue.ID, nil
 	}
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