feat(native): add iOS home screen widgets for continue watching and upcoming

- Add `ContinueWatching` (systemSmall) and `Upcoming` (systemSmall) SwiftUI widgets via `expo-widgets`, registered in `app.json` under the `group.com.jakejarvis.sofa` app group
- Add `widget-images` local Expo module with a Swift `WidgetImagesModule` that downloads and resizes remote poster images into the shared app group container for use by widgets; also copies bundled assets (sofa icon fallback)
- Add `src/lib/widgets.ts` to fetch dashboard data, cache poster images, and write a JSON timeline to the shared container via `expo-widgets`
- Add `ContinueWatching` and `Upcoming` SwiftUI widget views in `src/widgets/`
- Add `useWidgetRefresh` hook that refreshes widgets on foreground (throttled to once per minute) and on session ready
- Debounce widget refresh in `invalidateTitleQueries` so rapid mutations (e.g. marking multiple episodes watched) batch into a single refresh
- Expose `titles.upcoming` from the dashboard procedure and add `upcomingTitles` field to the dashboard schema
- Bump iOS deployment target to 16.2 (required by WidgetKit timeline APIs)

docs/public/openapi.json

@@ -2958,6 +2958,28 @@
                             ],
                             "description": "ThumbHash blur placeholder"
                           },
+                          "backdropPath": {
+                            "anyOf": [
+                              {
+                                "type": "string"
+                              },
+                              {
+                                "type": "null"
+                              }
+                            ],
+                            "description": "Backdrop image path"
+                          },
+                          "backdropThumbHash": {
+                            "anyOf": [
+                              {
+                                "type": "string"
+                              },
+                              {
+                                "type": "null"
+                              }
+                            ],
+                            "description": "ThumbHash blur placeholder for backdrop"
+                          },
                           "seasonNumber": {
                             "anyOf": [
                               {
@@ -3055,6 +3077,8 @@
                           "titleType",
                           "posterPath",
                           "posterThumbHash",
+                          "backdropPath",
+                          "backdropThumbHash",
                           "seasonNumber",
                           "episodeNumber",
                           "episodeName",