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/mod.rs

@@ -18,7 +18,8 @@ pub use auth::AuthState;
 pub use client::TdClient;
 pub use r#trait::TdClientTrait;
 pub use types::{
-    ChatInfo, FolderInfo, MessageBuilder, MessageInfo, NetworkState, ProfileInfo, ReplyInfo, UserOnlineStatus,
+    ChatInfo, FolderInfo, MediaInfo, MessageBuilder, MessageInfo, NetworkState, PhotoDownloadState,
+    PhotoInfo, ProfileInfo, ReplyInfo, UserOnlineStatus,
 };
 pub use users::UserCache;