fix(storage): persist close_reason to issues table on close (#551)

CloseIssue was storing the reason only in the events table, not in the
issues.close_reason column. This caused `bd show --json` to return an
empty close_reason even when one was provided.

- Update CloseIssue in queries.go and transaction.go to set close_reason
- Clear close_reason when reopening issues (in manageClosedAt)
- Add tests for close_reason in storage and CLI JSON output
- Document the dual-storage of close_reason (issues + events tables)

internal/storage/sqlite/queries.go

@@ -500,10 +500,13 @@ func manageClosedAt(oldIssue *types.Issue, updates map[string]interface{}, setCl
 		setClauses = append(setClauses, "closed_at = ?")
 		args = append(args, now)
 	} else if oldIssue.Status == types.StatusClosed {
-		// Changing from closed to something else: clear closed_at
+		// Changing from closed to something else: clear closed_at and close_reason
 		updates["closed_at"] = nil
 		setClauses = append(setClauses, "closed_at = ?")
 		args = append(args, nil)
+		updates["close_reason"] = ""
+		setClauses = append(setClauses, "close_reason = ?")
+		args = append(args, "")
 	}
 
 	return setClauses, args
@@ -806,10 +809,14 @@ func (s *SQLiteStorage) CloseIssue(ctx context.Context, id string, reason string
 	}
 	defer func() { _ = tx.Rollback() }()
 
+	// NOTE: close_reason is stored in two places:
+	// 1. issues.close_reason - for direct queries (bd show --json, exports)
+	// 2. events.comment - for audit history (when was it closed, by whom)
+	// Keep both in sync. If refactoring, consider deriving one from the other.
 	result, err := tx.ExecContext(ctx, `
-		UPDATE issues SET status = ?, closed_at = ?, updated_at = ?
+		UPDATE issues SET status = ?, closed_at = ?, updated_at = ?, close_reason = ?
 		WHERE id = ?
-	`, types.StatusClosed, now, now, id)
+	`, types.StatusClosed, now, now, reason, id)
 	if err != nil {
 		return fmt.Errorf("failed to close issue: %w", err)
 	}

internal/storage/sqlite/sqlite_test.go

@@ -706,6 +706,10 @@ func TestCloseIssue(t *testing.T) {
 	if closed.ClosedAt == nil {
 		t.Error("ClosedAt should be set")
 	}
+
+	if closed.CloseReason != "Done" {
+		t.Errorf("CloseReason not set: got %q, want %q", closed.CloseReason, "Done")
+	}
 }
 
 func TestClosedAtInvariant(t *testing.T) {
@@ -766,7 +770,7 @@ func TestClosedAtInvariant(t *testing.T) {
 			t.Fatalf("CloseIssue failed: %v", err)
 		}
 
-		// Verify it's closed with closed_at set
+		// Verify it's closed with closed_at and close_reason set
 		closed, err := store.GetIssue(ctx, issue.ID)
 		if err != nil {
 			t.Fatalf("GetIssue failed: %v", err)
@@ -774,6 +778,9 @@ func TestClosedAtInvariant(t *testing.T) {
 		if closed.ClosedAt == nil {
 			t.Fatal("ClosedAt should be set after closing")
 		}
+		if closed.CloseReason != "Done" {
+			t.Errorf("CloseReason should be 'Done', got %q", closed.CloseReason)
+		}
 
 		// Reopen the issue
 		updates := map[string]interface{}{
@@ -784,7 +791,7 @@ func TestClosedAtInvariant(t *testing.T) {
 			t.Fatalf("UpdateIssue failed: %v", err)
 		}
 
-		// Verify closed_at was cleared
+		// Verify closed_at and close_reason were cleared
 		reopened, err := store.GetIssue(ctx, issue.ID)
 		if err != nil {
 			t.Fatalf("GetIssue failed: %v", err)
@@ -795,6 +802,9 @@ func TestClosedAtInvariant(t *testing.T) {
 		if reopened.ClosedAt != nil {
 			t.Error("ClosedAt should be cleared when reopening issue")
 		}
+		if reopened.CloseReason != "" {
+			t.Errorf("CloseReason should be cleared when reopening issue, got %q", reopened.CloseReason)
+		}
 	})
 
 	t.Run("CreateIssue rejects closed issue without closed_at", func(t *testing.T) {

internal/storage/sqlite/transaction.go

@@ -462,13 +462,14 @@ func applyUpdatesToIssue(issue *types.Issue, updates map[string]interface{}) {
 }
 
 // CloseIssue closes an issue within the transaction.
+// NOTE: close_reason is stored in both issues table and events table - see SQLiteStorage.CloseIssue.
 func (t *sqliteTxStorage) CloseIssue(ctx context.Context, id string, reason string, actor string) error {
 	now := time.Now()
 
 	result, err := t.conn.ExecContext(ctx, `
-		UPDATE issues SET status = ?, closed_at = ?, updated_at = ?
+		UPDATE issues SET status = ?, closed_at = ?, updated_at = ?, close_reason = ?
 		WHERE id = ?
-	`, types.StatusClosed, now, now, id)
+	`, types.StatusClosed, now, now, reason, id)
 	if err != nil {
 		return fmt.Errorf("failed to close issue: %w", err)
 	}

internal/storage/sqlite/transaction_test.go

@@ -268,6 +268,9 @@ func TestTransactionCloseIssue(t *testing.T) {
 	if closed.Status != types.StatusClosed {
 		t.Errorf("expected status 'closed', got %q", closed.Status)
 	}
+	if closed.CloseReason != "Done" {
+		t.Errorf("expected close_reason 'Done', got %q", closed.CloseReason)
+	}
 }
 
 // TestTransactionDeleteIssue tests deleting an issue within a transaction.