feat: implement photo albums (media groups) and persist account selection

Group photos with shared media_album_id into single album bubbles with
grid layout (up to 3x cols). Album navigation treats grouped photos as
one unit (j/k skip entire album). Persist selected account to
accounts.toml so it survives app restart.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/tdlib/types.rs

@@ -107,6 +107,8 @@ pub struct MessageMetadata {
     pub date: i32,
     /// Дата редактирования (0 если не редактировалось)
     pub edit_date: i32,
+    /// ID медиа-альбома (0 если не часть альбома)
+    pub media_album_id: i64,
 }
 
 /// Контент сообщения (текст и форматирование)
@@ -175,6 +177,7 @@ impl MessageInfo {
                 sender_name,
                 date,
                 edit_date,
+                media_album_id: 0,
             },
             content: MessageContent {
                 text: content,
@@ -213,6 +216,10 @@ impl MessageInfo {
         self.metadata.edit_date > 0
     }
 
+    pub fn media_album_id(&self) -> i64 {
+        self.metadata.media_album_id
+    }
+
     pub fn text(&self) -> &str {
         &self.content.text
     }
@@ -337,6 +344,7 @@ pub struct MessageBuilder {
     forward_from: Option<ForwardInfo>,
     reactions: Vec<ReactionInfo>,
     media: Option<MediaInfo>,
+    media_album_id: i64,
 }
 
 impl MessageBuilder {
@@ -358,6 +366,7 @@ impl MessageBuilder {
             forward_from: None,
             reactions: Vec::new(),
             media: None,
+            media_album_id: 0,
         }
     }
 
@@ -461,6 +470,12 @@ impl MessageBuilder {
         self
     }
 
+    /// Установить ID медиа-альбома
+    pub fn media_album_id(mut self, id: i64) -> Self {
+        self.media_album_id = id;
+        self
+    }
+
     /// Построить MessageInfo из данных builder'а
     pub fn build(self) -> MessageInfo {
         let mut msg = MessageInfo::new(
@@ -480,6 +495,7 @@ impl MessageBuilder {
             self.reactions,
         );
         msg.content.media = self.media;
+        msg.metadata.media_album_id = self.media_album_id;
         msg
     }
 }