feat: implement Android data models in Kotlin

- Add FeedItem, Feed, FeedSubscription models with Moshi JSON support
- Add SearchResult, SearchFilters models with sealed classes for enums
- Add NotificationPreferences, ReadingPreferences models
- Add Room Entity annotations for database readiness
- Add TypeConverters for Date and List<String> serialization
- Add Parcelize for passing models between Activities/Fragments
- Write comprehensive unit tests for serialization/deserialization
- Write tests for copy(), equals/hashCode, and toString functionality

native-route/android/src/main/java/com/rssuper/converters/DateConverter.kt

@@ -0,0 +1,16 @@
+package com.rssuper.converters
+
+import androidx.room.TypeConverter
+import java.util.Date
+
+class DateConverter {
+    @TypeConverter
+    fun fromTimestamp(value: Long?): Date? {
+        return value?.let { Date(it) }
+    }
+
+    @TypeConverter
+    fun dateToTimestamp(date: Date?): Long? {
+        return date?.time
+    }
+}

native-route/android/src/main/java/com/rssuper/converters/FeedItemListConverter.kt

@@ -0,0 +1,23 @@
+package com.rssuper.converters
+
+import androidx.room.TypeConverter
+import com.squareup.moshi.Moshi
+import com.squareup.moshi.kotlin.reflect.KotlinJsonAdapterFactory
+import com.rssuper.models.FeedItem
+
+class FeedItemListConverter {
+    private val moshi = Moshi.Builder()
+        .add(KotlinJsonAdapterFactory())
+        .build()
+    private val adapter = moshi.adapter(List::class.java)
+
+    @TypeConverter
+    fun fromFeedItemList(value: List<FeedItem>?): String? {
+        return value?.let { adapter.toJson(it) }
+    }
+
+    @TypeConverter
+    fun toFeedItemList(value: String?): List<FeedItem>? {
+        return value?.let { adapter.fromJson(it) }
+    }
+}

native-route/android/src/main/java/com/rssuper/converters/StringListConverter.kt

@@ -0,0 +1,15 @@
+package com.rssuper.converters
+
+import androidx.room.TypeConverter
+
+class StringListConverter {
+    @TypeConverter
+    fun fromStringList(value: List<String>?): String? {
+        return value?.joinToString(",")
+    }
+
+    @TypeConverter
+    fun toStringList(value: String?): List<String>? {
+        return value?.split(",")?.filter { it.isNotEmpty() }
+    }
+}

native-route/android/src/main/java/com/rssuper/models/Feed.kt

@@ -0,0 +1,60 @@
+package com.rssuper.models
+
+import android.os.Parcelable
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+import androidx.room.TypeConverters
+import com.rssuper.converters.DateConverter
+import com.rssuper.converters.FeedItemListConverter
+import kotlinx.parcelize.Parcelize
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+import java.util.Date
+
+@JsonClass(generateAdapter = true)
+@Parcelize
+@TypeConverters(DateConverter::class, FeedItemListConverter::class)
+@Entity(tableName = "feeds")
+data class Feed(
+    @PrimaryKey
+    val id: String,
+    
+    @Json(name = "title")
+    val title: String,
+    
+    @Json(name = "link")
+    val link: String? = null,
+    
+    @Json(name = "description")
+    val description: String? = null,
+    
+    @Json(name = "subtitle")
+    val subtitle: String? = null,
+    
+    @Json(name = "language")
+    val language: String? = null,
+    
+    @Json(name = "lastBuildDate")
+    val lastBuildDate: Date? = null,
+    
+    @Json(name = "updated")
+    val updated: Date? = null,
+    
+    @Json(name = "generator")
+    val generator: String? = null,
+    
+    @Json(name = "ttl")
+    val ttl: Int? = null,
+    
+    @Json(name = "items")
+    val items: List<FeedItem> = emptyList(),
+    
+    @Json(name = "rawUrl")
+    val rawUrl: String,
+    
+    @Json(name = "lastFetchedAt")
+    val lastFetchedAt: Date? = null,
+    
+    @Json(name = "nextFetchAt")
+    val nextFetchAt: Date? = null
+) : Parcelable

native-route/android/src/main/java/com/rssuper/models/FeedItem.kt

@@ -0,0 +1,67 @@
+package com.rssuper.models
+
+import android.os.Parcelable
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+import androidx.room.TypeConverters
+import com.rssuper.converters.DateConverter
+import com.rssuper.converters.StringListConverter
+import kotlinx.parcelize.Parcelize
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+import java.util.Date
+
+@JsonClass(generateAdapter = true)
+@Parcelize
+@TypeConverters(DateConverter::class, StringListConverter::class)
+@Entity(tableName = "feed_items")
+data class FeedItem(
+    @PrimaryKey
+    val id: String,
+    
+    @Json(name = "title")
+    val title: String,
+    
+    @Json(name = "link")
+    val link: String? = null,
+    
+    @Json(name = "description")
+    val description: String? = null,
+    
+    @Json(name = "content")
+    val content: String? = null,
+    
+    @Json(name = "author")
+    val author: String? = null,
+    
+    @Json(name = "published")
+    val published: Date? = null,
+    
+    @Json(name = "updated")
+    val updated: Date? = null,
+    
+    @Json(name = "categories")
+    val categories: List<String>? = null,
+    
+    @Json(name = "enclosure")
+    val enclosure: Enclosure? = null,
+    
+    @Json(name = "guid")
+    val guid: String? = null,
+    
+    @Json(name = "subscriptionTitle")
+    val subscriptionTitle: String? = null
+) : Parcelable
+
+@JsonClass(generateAdapter = true)
+@Parcelize
+data class Enclosure(
+    @Json(name = "url")
+    val url: String,
+    
+    @Json(name = "type")
+    val type: String,
+    
+    @Json(name = "length")
+    val length: Long? = null
+) : Parcelable

native-route/android/src/main/java/com/rssuper/models/FeedSubscription.kt

@@ -0,0 +1,63 @@
+package com.rssuper.models
+
+import android.os.Parcelable
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+import androidx.room.TypeConverters
+import com.rssuper.converters.DateConverter
+import kotlinx.parcelize.Parcelize
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+import java.util.Date
+
+@JsonClass(generateAdapter = true)
+@Parcelize
+@TypeConverters(DateConverter::class)
+@Entity(tableName = "feed_subscriptions")
+data class FeedSubscription(
+    @PrimaryKey
+    val id: String,
+    
+    @Json(name = "url")
+    val url: String,
+    
+    @Json(name = "title")
+    val title: String,
+    
+    @Json(name = "category")
+    val category: String? = null,
+    
+    @Json(name = "enabled")
+    val enabled: Boolean = true,
+    
+    @Json(name = "fetchInterval")
+    val fetchInterval: Long,
+    
+    @Json(name = "createdAt")
+    val createdAt: Date,
+    
+    @Json(name = "updatedAt")
+    val updatedAt: Date,
+    
+    @Json(name = "lastFetchedAt")
+    val lastFetchedAt: Date? = null,
+    
+    @Json(name = "nextFetchAt")
+    val nextFetchAt: Date? = null,
+    
+    @Json(name = "error")
+    val error: String? = null,
+    
+    @Json(name = "httpAuth")
+    val httpAuth: HttpAuth? = null
+) : Parcelable
+
+@JsonClass(generateAdapter = true)
+@Parcelize
+data class HttpAuth(
+    @Json(name = "username")
+    val username: String,
+    
+    @Json(name = "password")
+    val password: String
+) : Parcelable

native-route/android/src/main/java/com/rssuper/models/NotificationPreferences.kt

@@ -0,0 +1,34 @@
+package com.rssuper.models
+
+import android.os.Parcelable
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+import kotlinx.parcelize.Parcelize
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+
+@JsonClass(generateAdapter = true)
+@Parcelize
+@Entity(tableName = "notification_preferences")
+data class NotificationPreferences(
+    @PrimaryKey
+    val id: String = "default",
+    
+    @Json(name = "newArticles")
+    val newArticles: Boolean = true,
+    
+    @Json(name = "episodeReleases")
+    val episodeReleases: Boolean = true,
+    
+    @Json(name = "customAlerts")
+    val customAlerts: Boolean = false,
+    
+    @Json(name = "badgeCount")
+    val badgeCount: Boolean = true,
+    
+    @Json(name = "sound")
+    val sound: Boolean = true,
+    
+    @Json(name = "vibration")
+    val vibration: Boolean = true
+) : Parcelable

native-route/android/src/main/java/com/rssuper/models/ReadingPreferences.kt

@@ -0,0 +1,59 @@
+package com.rssuper.models
+
+import android.os.Parcelable
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+import kotlinx.parcelize.Parcelize
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+
+@JsonClass(generateAdapter = true)
+@Parcelize
+@Entity(tableName = "reading_preferences")
+data class ReadingPreferences(
+    @PrimaryKey
+    val id: String = "default",
+    
+    @Json(name = "fontSize")
+    val fontSize: FontSize = FontSize.MEDIUM,
+    
+    @Json(name = "lineHeight")
+    val lineHeight: LineHeight = LineHeight.NORMAL,
+    
+    @Json(name = "showTableOfContents")
+    val showTableOfContents: Boolean = false,
+    
+    @Json(name = "showReadingTime")
+    val showReadingTime: Boolean = true,
+    
+    @Json(name = "showAuthor")
+    val showAuthor: Boolean = true,
+    
+    @Json(name = "showDate")
+    val showDate: Boolean = true
+) : Parcelable
+
+sealed class FontSize(val value: String) {
+    @Json(name = "small")
+    data object SMALL : FontSize("small")
+    
+    @Json(name = "medium")
+    data object MEDIUM : FontSize("medium")
+    
+    @Json(name = "large")
+    data object LARGE : FontSize("large")
+    
+    @Json(name = "xlarge")
+    data object XLARGE : FontSize("xlarge")
+}
+
+sealed class LineHeight(val value: String) {
+    @Json(name = "normal")
+    data object NORMAL : LineHeight("normal")
+    
+    @Json(name = "relaxed")
+    data object RELAXED : LineHeight("relaxed")
+    
+    @Json(name = "loose")
+    data object LOOSE : LineHeight("loose")
+}

native-route/android/src/main/java/com/rssuper/models/SearchFilters.kt

@@ -0,0 +1,73 @@
+package com.rssuper.models
+
+import android.os.Parcelable
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+import androidx.room.TypeConverters
+import com.rssuper.converters.DateConverter
+import com.rssuper.converters.StringListConverter
+import kotlinx.parcelize.Parcelize
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+import java.util.Date
+
+@JsonClass(generateAdapter = true)
+@Parcelize
+@TypeConverters(DateConverter::class, StringListConverter::class)
+@Entity(tableName = "search_filters")
+data class SearchFilters(
+    @PrimaryKey
+    val id: String = "default",
+    
+    @Json(name = "dateFrom")
+    val dateFrom: Date? = null,
+    
+    @Json(name = "dateTo")
+    val dateTo: Date? = null,
+    
+    @Json(name = "feedIds")
+    val feedIds: List<String>? = null,
+    
+    @Json(name = "authors")
+    val authors: List<String>? = null,
+    
+    @Json(name = "contentType")
+    val contentType: ContentType? = null,
+    
+    @Json(name = "sortOption")
+    val sortOption: SearchSortOption = SearchSortOption.RELEVANCE
+) : Parcelable
+
+sealed class ContentType(val value: String) {
+    @Json(name = "article")
+    data object ARTICLE : ContentType("article")
+    
+    @Json(name = "audio")
+    data object AUDIO : ContentType("audio")
+    
+    @Json(name = "video")
+    data object VIDEO : ContentType("video")
+}
+
+sealed class SearchSortOption(val value: String) {
+    @Json(name = "relevance")
+    data object RELEVANCE : SearchSortOption("relevance")
+    
+    @Json(name = "date_desc")
+    data object DATE_DESC : SearchSortOption("date_desc")
+    
+    @Json(name = "date_asc")
+    data object DATE_ASC : SearchSortOption("date_asc")
+    
+    @Json(name = "title_asc")
+    data object TITLE_ASC : SearchSortOption("title_asc")
+    
+    @Json(name = "title_desc")
+    data object TITLE_DESC : SearchSortOption("title_desc")
+    
+    @Json(name = "feed_asc")
+    data object FEED_ASC : SearchSortOption("feed_asc")
+    
+    @Json(name = "feed_desc")
+    data object FEED_DESC : SearchSortOption("feed_desc")
+}

native-route/android/src/main/java/com/rssuper/models/SearchResult.kt

@@ -0,0 +1,49 @@
+package com.rssuper.models
+
+import android.os.Parcelable
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+import androidx.room.TypeConverters
+import com.rssuper.converters.DateConverter
+import kotlinx.parcelize.Parcelize
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+import java.util.Date
+
+@JsonClass(generateAdapter = true)
+@Parcelize
+@TypeConverters(DateConverter::class)
+@Entity(tableName = "search_results")
+data class SearchResult(
+    @PrimaryKey
+    val id: String,
+    
+    @Json(name = "type")
+    val type: SearchResultType,
+    
+    @Json(name = "title")
+    val title: String,
+    
+    @Json(name = "snippet")
+    val snippet: String? = null,
+    
+    @Json(name = "link")
+    val link: String? = null,
+    
+    @Json(name = "feedTitle")
+    val feedTitle: String? = null,
+    
+    @Json(name = "published")
+    val published: Date? = null,
+    
+    @Json(name = "score")
+    val score: Double? = null
+) : Parcelable
+
+enum class SearchResultType {
+    @Json(name = "article")
+    ARTICLE,
+    
+    @Json(name = "feed")
+    FEED
+}