Fix bd-dvd and bd-ymj: Parent resurrection and export metadata

Bug 1 (bd-dvd): GetNextChildID now attempts parent resurrection from JSONL
before failing. Added TryResurrectParent call to match CreateIssue behavior.

Bug 2 (bd-ymj): Export now updates last_import_hash metadata to prevent
'JSONL content has changed' errors on subsequent exports.

Files changed:
- internal/storage/sqlite/hash_ids.go: Add resurrection attempt
- cmd/bd/daemon_sync.go: Add metadata updates after export
- Tests added for both fixes
- Fixed pre-existing bug in integrity_content_test.go

Follow-up work tracked in epic bd-ar2 (9 issues for improvements).

Fixes GH #334

cmd/bd/integrity_content_test.go

@@ -27,6 +27,8 @@ func TestContentBasedComparison(t *testing.T) {
 	dbPath := filepath.Join(beadsDir, "beads.db")
 	jsonlPath := filepath.Join(beadsDir, "issues.jsonl")
 
+	ctx := context.Background()
+
 	// Create and populate database
 	localStore, err := sqlite.New(ctx, dbPath)
 	if err != nil {
@@ -34,8 +36,6 @@ func TestContentBasedComparison(t *testing.T) {
 	}
 	defer localStore.Close()
 
-	ctx := context.Background()
-
 	// Initialize database with issue_prefix
 	if err := localStore.SetConfig(ctx, "issue_prefix", "test"); err != nil {
 		t.Fatalf("Failed to set issue_prefix: %v", err)
@@ -179,6 +179,8 @@ func TestContentHashComputation(t *testing.T) {
 	dbPath := filepath.Join(beadsDir, "beads.db")
 	jsonlPath := filepath.Join(beadsDir, "issues.jsonl")
 
+	ctx := context.Background()
+
 	// Create and populate database
 	localStore, err := sqlite.New(ctx, dbPath)
 	if err != nil {
@@ -186,8 +188,6 @@ func TestContentHashComputation(t *testing.T) {
 	}
 	defer localStore.Close()
 
-	ctx := context.Background()
-
 	if err := localStore.SetConfig(ctx, "issue_prefix", "test"); err != nil {
 		t.Fatalf("Failed to set issue_prefix: %v", err)
 	}