ui: Constants refactor (#26908)

* refactor: Constants

* refactor: Constants/Enums cleanup

* refactor: Constant objects instead of multiple single value constants

* refactor: Cleanup constants

tools/ui/src/lib/constants/database.constants.ts

@@ -0,0 +1,29 @@
+/**
+ * Database-related constants (IndexedDB, Dexie).
+ *
+ * Centralized to ensure consistency across the app and simplify future
+ * naming changes.
+ */
+
+import { STORAGE_APP_NAME } from './storage.constants';
+
+/** IndexedDB database name */
+export const DB_NAME = STORAGE_APP_NAME;
+
+/** IndexedDB store / table names */
+export const IDXDB_TABLES = {
+	conversations: 'conversations',
+	messages: 'messages'
+} as const;
+
+/** IndexedDB store schemas */
+export const IDXDB_STORE_SCHEMAS = {
+	conversations: 'id, lastModified, currNode, name',
+	messages: 'id, convId, type, role, timestamp, parent, children'
+} as const;
+
+/** Combined Dexie stores definition — keys are table names, values are schemas */
+export const IDXDB_STORES = {
+	[IDXDB_TABLES.conversations]: IDXDB_STORE_SCHEMAS.conversations,
+	[IDXDB_TABLES.messages]: IDXDB_STORE_SCHEMAS.messages
+} as const;