feat: implement Phase 11 — inline photo viewing with ratatui-image

Add feature-gated (`images`) inline photo support:
- New types: MediaInfo, PhotoInfo, PhotoDownloadState, ImagesConfig
- Media module: ImageCache (LRU filesystem cache), ImageRenderer (terminal protocol detection)
- Photo metadata extraction from TDLib MessagePhoto with download_file() API
- ViewImage command (v/м) to toggle photo expand/collapse in message selection
- Two-pass UI rendering: placeholder lines in message bubbles + StatefulImage overlay
- Collapse all expanded photos on Esc (exit selection mode)

Dependencies: ratatui-image 8.1, image 0.25 (optional, behind `images` feature flag)

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

src/tdlib/message_conversion.rs

@@ -7,7 +7,7 @@ use crate::types::MessageId;
 use tdlib_rs::enums::{MessageContent, MessageSender};
 use tdlib_rs::types::Message as TdMessage;
 
-use super::types::{ForwardInfo, ReactionInfo, ReplyInfo};
+use super::types::{ForwardInfo, MediaInfo, PhotoDownloadState, PhotoInfo, ReactionInfo, ReplyInfo};
 
 /// Извлекает текст контента из TDLib Message
 ///
@@ -19,9 +19,9 @@ pub fn extract_content_text(msg: &TdMessage) -> String {
         MessageContent::MessagePhoto(p) => {
             let caption_text = p.caption.text.clone();
             if caption_text.is_empty() {
-                "[Фото]".to_string()
+                "📷 [Фото]".to_string()
             } else {
-                caption_text
+                format!("📷 {}", caption_text)
             }
         }
         MessageContent::MessageVideo(v) => {
@@ -132,6 +132,40 @@ pub fn extract_reply_info(msg: &TdMessage) -> Option<ReplyInfo> {
     })
 }
 
+/// Извлекает информацию о медиа-контенте из TDLib Message
+///
+/// Для MessagePhoto: получает лучший размер фото, извлекает file_id, width, height.
+/// Возвращает None для не-медийных типов сообщений.
+pub fn extract_media_info(msg: &TdMessage) -> Option<MediaInfo> {
+    match &msg.content {
+        MessageContent::MessagePhoto(p) => {
+            // Берём лучший (последний = самый большой) размер фото
+            let best_size = p.photo.sizes.last()?;
+            let file_id = best_size.photo.id;
+            let width = best_size.width;
+            let height = best_size.height;
+
+            // Проверяем, скачан ли файл
+            let download_state = if !best_size.photo.local.path.is_empty()
+                && best_size.photo.local.is_downloading_completed
+            {
+                PhotoDownloadState::Downloaded(best_size.photo.local.path.clone())
+            } else {
+                PhotoDownloadState::NotDownloaded
+            };
+
+            Some(MediaInfo::Photo(PhotoInfo {
+                file_id,
+                width,
+                height,
+                download_state,
+                expanded: false,
+            }))
+        }
+        _ => None,
+    }
+}
+
 /// Извлекает реакции из TDLib Message
 pub fn extract_reactions(msg: &TdMessage) -> Vec<ReactionInfo> {
     msg.interaction_info