Implement user onboarding and enhanced .strm file creation

- Added automated onboarding dialog for new users to pick genres, eras, and content types.
- Enhanced "Add Movie" functionality to support folder-per-movie structure with Year and IMDb ID.
- Improved ui.js with custom dialogs for Onboarding, Rating, and Adding Movies.
- Fixed API accessibility by using standard [Authorize] attributes.
- Added "Mark Viewed" and "Sync" actions to the UI.

Co-authored-by: devitq <118541411+devitq@users.noreply.github.com>

src/main/kotlin/com/project/movienight/domain/model/FilmLibrary.kt

@@ -1,5 +1,6 @@
 package com.project.movienight.domain.model
 
+import java.time.LocalDateTime
 import java.util.UUID
 
 data class FilmLibrary(
@@ -8,4 +9,5 @@ data class FilmLibrary(
     val filmId: UUID,
     val comment: String?,
     val isViewed: Boolean,
+    val watchedAt: LocalDateTime? = null,
 )