fix(favorites): save server favourites through to the cache (DR-115)

The hybrid favourites read went straight to the online repository on a
cache miss and dropped the result on the floor. Every other read path
persists what it fetches, so this one made the favourites page re-query
the server on every visit — and left the offline mirror (DR-114) empty on
a fresh install, since this is the path that fills it.

It now goes through get_favorites_server_only, which saves through on the
way back.

The command had a matching hole: with nothing cached it returned the empty
result, painting "Nothing favourited yet" at a viewer whose favourites
were simply marked on another client. It now asks the repository for a
real answer instead of an empty state it would correct a round trip later.

TRACES: UR-067 | DR-115

docs/requirements.md

@@ -283,7 +283,7 @@ Internal architecture, components, and application logic.
 | DR-112 | Safe-area insets come from **native**, not from `env()` alone. `env(safe-area-inset-*)` is 0px without `viewport-fit=cover` (missing from `app.html`, so every safe-area rule in the app was already a no-op), and even with it Android WebView maps only the *display cutout* — never the status bar or navigation bar. Since `enableEdgeToEdge()` plus `targetSdk 36` make edge-to-edge unconditional, the WebView always spans the system bars, so CSS could not learn about them by any route. `WindowInsetsBridge` reads the real insets and publishes `jt-inset` custom properties; `app.css` folds them with `env()` via `max()` into `--safe-*`, which is the only thing components may pad from. Ownership is exactly one element per edge: the app shell takes top/left/right, and BottomUi takes bottom wherever it renders (`shellReservesBottomInset` hands it back to the shell on routes with no bottom UI) so the padding sits inside BottomUi's surface box and the colour extends behind the gesture bar. The full-screen players inset their control layers only, leaving video and artwork edge-to-edge. The theme's `fitsSystemWindows=true` — which claimed the opposite and was overridden at runtime and ignored at this target SDK — is removed | UI | UR-066 | Done |
 | DR-113 | `MediaItem.user_data` is populated from the server instead of being hardcoded `None`. `JellyfinItem` gains a `UserData` field (`#[serde(alias = "UserData")]` → the existing `UserData` type) and `to_media_item` maps it, so every list and detail response carries favourite/played/resume state. `UserData` is named explicitly in the `Fields=` list rather than relying on Jellyfin's default. Without this no card or detail page can render a favourite it did not itself set, and the mini player's per-track `storageGetPlaybackProgress` fetch is the only way to colour one heart | Repository | UR-069 | Done |
 | DR-114 | Server favourite state is mirrored into the local `user_data` table by `OfflineRepository::save_to_cache` — the single choke point every cached server result passes through — so offline browsing and the offline Favourites page see the same favourites as the server. The upsert carries `pending_sync = 0` and is guarded by `WHERE user_data.pending_sync = 0`, which is the conflict rule: a toggle made offline is never overwritten by a stale server value before it has been pushed | Storage | UR-069 | Done |
-| DR-115 | Cross-library favourites query: a `get_favorites(scope, options)` repository method plus the `repository_get_favorites` command. Online issues `Filters=IsFavorite&Recursive=true` with `IncludeItemTypes` expanded from `SearchScope::item_types()` in Rust (the frontend sends the opaque scope, never a type list — DR-063); offline reads `items ⨝ user_data (is_favorite = 1)` under the same `include_catalog_browse()` gate as browsing; hybrid races cache against server like `get_items`, including the DR-080 rule that an empty offline result is authoritative when the gate is off. A separate method rather than `get_items` because favourites span libraries and `get_items` is `ParentId`-shaped | Repository | UR-067 | Done |
+| DR-115 | Cross-library favourites query: a `get_favorites(scope, options)` repository method plus the `repository_get_favorites` command. Online issues `Filters=IsFavorite&Recursive=true` with `IncludeItemTypes` expanded from `SearchScope::item_types()` in Rust (the frontend sends the opaque scope, never a type list — DR-063); offline reads `items ⨝ user_data (is_favorite = 1)` under the same `include_catalog_browse()` gate as browsing; hybrid races cache against server like `get_items` — saving server results through to the cache on a miss, so the favourites page does not re-query the server every visit and the DR-114 mirror is filled on a fresh install — and applies the DR-080 rule that an empty offline result is authoritative when the gate is off. The command falls back to this read when nothing is cached, rather than painting an empty state it will correct a round trip later. A separate method rather than `get_items` because favourites span libraries and `get_items` is `ParentId`-shaped | Repository | UR-067 | Done |
 | DR-116 | `GetItemsOptions.favorites_only` filters an existing library listing in place — online by appending `Filters=IsFavorite`, offline by joining `user_data` into the existing `available_items` CTE so the downloads-only gate still applies. This is what backs the per-library favourites toggle, and composes with the genre and item-type filters already there | Repository | UR-067 | Done |
 | DR-117 | The Favourites page (`/library/favorites`) renders favourites across libraries with All / Movies / Shows / Music scope tabs, reusing `LibraryViewTabs` + `LibraryGrid` + `MediaCard` so card shape still follows the media (§5A.1) and a mixed All tab reads as posters, squares and thumbnails side by side. Each tab sends a `SearchScope` value and nothing else. Reached from the library overview and from "See all" on the home rows | UI | UR-067 | Done |
 | DR-118 | Home carries favourite rows for movies, shows and music, loaded via `repository_get_favorites` per scope and rendered below Recently Added. A row with no items does not render at all, so a fresh install shows no empty favourite rows | UI | UR-067 | Done |