Fix transaction conflict in TryResurrectParent (bd-58c0)

Refactored resurrection functions to accept optional *sql.Conn parameter:
- Added tryResurrectParentWithConn() internal function
- Added tryResurrectParentChainWithConn() internal function
- Updated CreateIssue to use conn-based resurrection
- Updated EnsureIDs to use conn-based resurrection

This eliminates 'database is locked' errors when resurrection
happens inside an existing transaction.

Fixes bd-58c0

internal/storage/sqlite/child_id_test.go

@@ -197,7 +197,9 @@ func TestCreateIssue_HierarchicalID_ParentNotExists(t *testing.T) {
 	if err == nil {
 		t.Errorf("expected error for child without parent, got nil")
 	}
-	if err != nil && err.Error() != "parent issue bd-nonexistent does not exist" {
-		t.Errorf("unexpected error message: %v", err)
+	// With resurrection feature, error message includes JSONL history check
+	expectedErr := "parent issue bd-nonexistent does not exist and could not be resurrected from JSONL history"
+	if err != nil && err.Error() != expectedErr {
+		t.Errorf("unexpected error message: got %q, want %q", err.Error(), expectedErr)
 	}
 }