feat(import): implement parent resurrection (bd-cc4f, bd-d76d, bd-02a4)

Phase 2 of fixing import failure on missing parent issues (bd-d19a).

Implemented:
- TryResurrectParent: searches JSONL history for deleted parents
- TryResurrectParentChain: recursively resurrects entire parent chains
- Creates tombstones (status=closed) to preserve hierarchical structure
- Modified EnsureIDs and CreateIssue to call resurrection before validation

When importing a child issue with missing parent:
1. Searches .beads/issues.jsonl for parent in git history
2. If found, creates tombstone with status=closed
3. Preserves original title and metadata
4. Appends original description to tombstone
5. Copies dependencies if targets exist

This allows imports to proceed even when parents were deleted,
enabling multi-repo workflows and normal database hygiene operations.

Part of bd-d19a (fix import failure on missing parents).

Amp-Thread-ID: https://ampcode.com/threads/T-a1c9e824-885e-40ce-a179-148cf39c7e64
Co-authored-by: Amp <amp@ampcode.com>

internal/storage/sqlite/sqlite.go

@@ -179,20 +179,19 @@ func (s *SQLiteStorage) CreateIssue(ctx context.Context, issue *types.Issue, act
 			return err
 		}
 		
-		// For hierarchical IDs (bd-a3f8e9.1), validate parent exists
+		// For hierarchical IDs (bd-a3f8e9.1), ensure parent exists
 		if strings.Contains(issue.ID, ".") {
-			// Extract parent ID (everything before the last dot)
-			lastDot := strings.LastIndex(issue.ID, ".")
-			parentID := issue.ID[:lastDot]
-			
-			var parentCount int
-			err = conn.QueryRowContext(ctx, `SELECT COUNT(*) FROM issues WHERE id = ?`, parentID).Scan(&parentCount)
-			if err != nil {
-				return fmt.Errorf("failed to check parent existence: %w", err)
-			}
-			if parentCount == 0 {
-				return fmt.Errorf("parent issue %s does not exist", parentID)
-			}
+		// Try to resurrect entire parent chain if any parents are missing
+		resurrected, err := s.TryResurrectParentChain(ctx, issue.ID)
+		if err != nil {
+		 return fmt.Errorf("failed to resurrect parent chain for %s: %w", issue.ID, err)
+		}
+		if !resurrected {
+		 // Parent(s) not found in JSONL history - cannot proceed
+		lastDot := strings.LastIndex(issue.ID, ".")
+		 parentID := issue.ID[:lastDot]
+		 return fmt.Errorf("parent issue %s does not exist and could not be resurrected from JSONL history", parentID)
+		}
 		}
 	}