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>

tests/messages.rs

@@ -387,3 +387,118 @@ fn snapshot_selected_message() {
     let output = buffer_to_string(&buffer);
     assert_snapshot!("selected_message", output);
 }
+
+#[test]
+fn snapshot_album_incoming() {
+    let chat = create_test_chat("Mom", 123);
+    let msg1 = TestMessageBuilder::new("📷 [Фото]", 1)
+        .sender("Alice")
+        .media_album_id(12345)
+        .build();
+    let msg2 = TestMessageBuilder::new("Caption for album", 2)
+        .sender("Alice")
+        .media_album_id(12345)
+        .build();
+    let msg3 = TestMessageBuilder::new("📷 [Фото]", 3)
+        .sender("Alice")
+        .media_album_id(12345)
+        .build();
+
+    let mut app = TestAppBuilder::new()
+        .with_chat(chat)
+        .with_messages(123, vec![msg1, msg2, msg3])
+        .selected_chat(123)
+        .build();
+
+    let buffer = render_to_buffer(80, 24, |f| {
+        tele_tui::ui::messages::render(f, f.area(), &mut app);
+    });
+
+    let output = buffer_to_string(&buffer);
+    assert_snapshot!("album_incoming", output);
+}
+
+#[test]
+fn snapshot_album_outgoing() {
+    let chat = create_test_chat("Mom", 123);
+    let msg1 = TestMessageBuilder::new("📷 [Фото]", 1)
+        .outgoing()
+        .media_album_id(99999)
+        .build();
+    let msg2 = TestMessageBuilder::new("My vacation photos", 2)
+        .outgoing()
+        .media_album_id(99999)
+        .build();
+
+    let mut app = TestAppBuilder::new()
+        .with_chat(chat)
+        .with_messages(123, vec![msg1, msg2])
+        .selected_chat(123)
+        .build();
+
+    let buffer = render_to_buffer(80, 24, |f| {
+        tele_tui::ui::messages::render(f, f.area(), &mut app);
+    });
+
+    let output = buffer_to_string(&buffer);
+    assert_snapshot!("album_outgoing", output);
+}
+
+#[test]
+fn snapshot_album_with_regular_messages() {
+    let chat = create_test_chat("Group Chat", 123);
+    let msg1 = TestMessageBuilder::new("Regular message before", 1)
+        .sender("Alice")
+        .build();
+    let msg2 = TestMessageBuilder::new("📷 [Фото]", 2)
+        .sender("Alice")
+        .media_album_id(555)
+        .build();
+    let msg3 = TestMessageBuilder::new("Album caption", 3)
+        .sender("Alice")
+        .media_album_id(555)
+        .build();
+    let msg4 = TestMessageBuilder::new("Regular message after", 4)
+        .sender("Alice")
+        .build();
+
+    let mut app = TestAppBuilder::new()
+        .with_chat(chat)
+        .with_messages(123, vec![msg1, msg2, msg3, msg4])
+        .selected_chat(123)
+        .build();
+
+    let buffer = render_to_buffer(80, 24, |f| {
+        tele_tui::ui::messages::render(f, f.area(), &mut app);
+    });
+
+    let output = buffer_to_string(&buffer);
+    assert_snapshot!("album_with_regular_messages", output);
+}
+
+#[test]
+fn snapshot_album_selected() {
+    let chat = create_test_chat("Mom", 123);
+    let msg1 = TestMessageBuilder::new("📷 [Фото]", 1)
+        .sender("Alice")
+        .media_album_id(777)
+        .build();
+    let msg2 = TestMessageBuilder::new("📷 [Фото]", 2)
+        .sender("Alice")
+        .media_album_id(777)
+        .build();
+
+    let mut app = TestAppBuilder::new()
+        .with_chat(chat)
+        .with_messages(123, vec![msg1, msg2])
+        .selected_chat(123)
+        .selecting_message(1) // Выбираем одно из сообщений альбома
+        .build();
+
+    let buffer = render_to_buffer(80, 24, |f| {
+        tele_tui::ui::messages::render(f, f.area(), &mut app);
+    });
+
+    let output = buffer_to_string(&buffer);
+    assert_snapshot!("album_selected", output);
+}