General improvments (#114)

* Add "Keep Screen On" feature to PDF and Epub readers.

* Add `rawLibraryFiles` to `MainViewModel` and improve file path resolution in `SharedComposables`.

Specifically:
- Updated `MainViewModel` state and UI logic to track and provide unfiltered library files.
- Enhanced file path formatting in `SharedComposables` to better handle Document, Tree, and primary storage URIs.
- Added scrollable support for long text values in `DetailItem` composable.
- Passed `rawLibraryFiles` to `FolderSyncScreen` to ensure sync logic uses the base file list.

* Update info bar background and text colors in EpubReaderScreen to match the selected theme.

* Prevent accidental UI bar toggles immediately after scrolling in EPUB vertical mode.

* feat: implement EPUB highlights sync and legacy migration

- Implement Cloud and Local Folder sync for EPUB highlights.
- Add highlight JSON serialization/deserialization helpers in EpubReaderAnnotations.
- Implement automatic migration of highlights from SharedPreferences to the Database on book open.
- Add cleanup logic to remove legacy SharedPreferences data after successful DB migration.
- Update RecentFilesRepository to trigger local folder metadata sync when highlights are modified.
- Update FolderSyncWorker to pull highlights and custom names from linked folder metadata.

* Update intent filters

app/src/main/java/com/aryan/reader/FolderSyncWorker.kt

@@ -152,6 +152,8 @@ class FolderSyncWorker(
                             lastPositionCfi = remoteMeta.lastPositionCfi,
                             progressPercentage = remoteMeta.progressPercentage,
                             bookmarksJson = remoteMeta.bookmarksJson,
+                            highlightsJson = remoteMeta.highlightsJson,
+                            customName = remoteMeta.customName,
                             locatorBlockIndex = remoteMeta.locatorBlockIndex,
                             locatorCharOffset = remoteMeta.locatorCharOffset,
                             lastModifiedTimestamp = remoteMeta.lastModifiedTimestamp,
@@ -247,6 +249,8 @@ class FolderSyncWorker(
                             lastPositionCfi = remoteMeta?.lastPositionCfi,
                             progressPercentage = remoteMeta?.progressPercentage,
                             bookmarksJson = remoteMeta?.bookmarksJson,
+                            highlightsJson = remoteMeta?.highlightsJson,
+                            customName = remoteMeta?.customName,
                             locatorBlockIndex = remoteMeta?.locatorBlockIndex,
                             locatorCharOffset = remoteMeta?.locatorCharOffset
                         )