fix(backup): export and restore hidden Xtream categories by real xtream IDs (#1224)

Category rows crossed the DB-worker IPC boundary with Drizzle's camelCase
property names while the renderer contracts declare snake_case, so backup
export dropped hidden-category IDs and restore degraded to a type-only
match that hid every category. Project category ops to the declared wire
shape, normalize restore state from untrusted sources (dropping entries
without a numeric xtreamId), reject entries with missing user-state
collections, and add full export→import round-trip coverage (unit
manifest-equality + Electron e2e) plus regression tests.

Closes #1017

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

apps/electron-backend/src/app/database/operations/category.operations.spec.ts

@@ -1,6 +1,23 @@
 import type { AppDatabase } from '../database.types';
 import * as schema from '@iptvnator/shared/database/schema';
-import { getCategories, saveCategories } from './category.operations';
+import {
+    getAllCategories,
+    getCategories,
+    saveCategories,
+} from './category.operations';
+
+// Renderer consumers (XCategoryFromDb/XtreamCategoryFromDb) expect category
+// rows in this snake_case wire shape. A bare select() would return Drizzle's
+// camelCase property names and silently break the playlist backup
+// export/restore (issue #1017).
+const categoryWireShape = {
+    id: schema.categories.id,
+    playlist_id: schema.categories.playlistId,
+    name: schema.categories.name,
+    type: schema.categories.type,
+    xtream_id: schema.categories.xtreamId,
+    hidden: schema.categories.hidden,
+};
 
 function createDbMock(existingCount = 0) {
     const where = jest.fn().mockResolvedValue([{ count: existingCount }]);
@@ -37,6 +54,21 @@ describe('category.operations', () => {
         await getCategories(db, 'playlist-1', 'live');
 
         expect(orderBy).toHaveBeenCalledWith(schema.categories.id);
+        expect(select).toHaveBeenCalledWith(categoryWireShape);
+    });
+
+    it('projects all categories to the snake_case wire shape', async () => {
+        const orderBy = jest.fn().mockResolvedValue([]);
+        const where = jest.fn().mockReturnValue({ orderBy });
+        const from = jest.fn().mockReturnValue({ where });
+        const select = jest.fn().mockReturnValue({ from });
+        const db = {
+            select,
+        } as unknown as AppDatabase;
+
+        await getAllCategories(db, 'playlist-1', 'movies');
+
+        expect(select).toHaveBeenCalledWith(categoryWireShape);
     });
 
     it('restores hidden categories when Xtream API category IDs are strings', async () => {

apps/electron-backend/src/app/database/operations/category.operations.ts

@@ -7,6 +7,20 @@ type XtreamCategoryInput = {
     category_id: string | number;
 };
 
+// Category rows cross the DB-worker IPC boundary in the snake_case wire
+// shape declared by XCategoryFromDb/XtreamCategoryFromDb. A bare select()
+// would leak Drizzle's camelCase property names (xtreamId, playlistId)
+// instead, silently breaking consumers such as the playlist backup
+// export/restore (issue #1017).
+const categoryWireShape = {
+    id: schema.categories.id,
+    playlist_id: schema.categories.playlistId,
+    name: schema.categories.name,
+    type: schema.categories.type,
+    xtream_id: schema.categories.xtreamId,
+    hidden: schema.categories.hidden,
+};
+
 function normalizeXtreamCategoryId(
     rawCategoryId: string | number
 ): number | null {
@@ -43,7 +57,7 @@ export async function getCategories(
     // If partial category re-inserts are added later, persist a provider
     // sort index instead of relying on the insertion id.
     return db
-        .select()
+        .select(categoryWireShape)
         .from(schema.categories)
         .where(
             and(
@@ -123,7 +137,7 @@ export async function getAllCategories(
     type: 'live' | 'movies' | 'series'
 ) {
     return db
-        .select()
+        .select(categoryWireShape)
         .from(schema.categories)
         .where(
             and(