fix(dbml): resolve commented cross-file // Ref: lines

Commented refs are collected per file and resolved against the combined
model after all inputs are loaded (directory, --from-list, merge, jobs).
Matched refs become FKs and relationships; duplicates of existing FKs are
skipped; missing targets are skipped with a warning; column type
mismatches warn.

Also keep reused index names within a DBML table instead of overwriting,
give a second FK to the same table a distinct relationship name, and make
the pgsql writer match relationships to FKs by name first.

pkg/readers/dbml/reader_test.go

@@ -1085,3 +1085,39 @@ func TestReader_MultilineTableNote(t *testing.T) {
 		t.Errorf("column note = %q, want %q", got, want)
 	}
 }
+
+// A name reused inside one Indexes block must not silently drop the earlier
+// index; both are kept so the inspector can report the duplicate.
+func TestReader_DuplicateIndexNameInTableKept(t *testing.T) {
+	dbmlContent := `Table individual_actor {
+  id bigint [pk]
+  rid_actor bigint
+  kind text
+
+  Indexes {
+    (rid_actor) [name: 'idx_actor', unique]
+    (rid_actor, kind) [name: 'idx_actor']
+  }
+}
+`
+	dir := t.TempDir()
+	path := filepath.Join(dir, "dup_index.dbml")
+	if err := os.WriteFile(path, []byte(dbmlContent), 0o644); err != nil {
+		t.Fatalf("failed to write fixture: %v", err)
+	}
+
+	db, err := NewReader(&readers.ReaderOptions{FilePath: path}).ReadDatabase()
+	if err != nil {
+		t.Fatalf("ReadDatabase() error = %v", err)
+	}
+
+	table := db.Schemas[0].Tables[0]
+	if len(table.Indexes) != 2 {
+		t.Fatalf("expected 2 indexes, got %d: %v", len(table.Indexes), table.Indexes)
+	}
+	for key, idx := range table.Indexes {
+		if idx.Name != "idx_actor" {
+			t.Errorf("index %q: Name = %q, want idx_actor", key, idx.Name)
+		}
+	}
+}