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/ui/components/mod.rs

@@ -12,4 +12,6 @@ pub use input_field::render_input_field;
 pub use chat_list_item::render_chat_list_item;
 pub use emoji_picker::render_emoji_picker;
 pub use message_bubble::{render_date_separator, render_message_bubble, render_sender_header};
+#[cfg(feature = "images")]
+pub use message_bubble::{DeferredImageRender, calculate_image_height};
 pub use message_list::{render_message_item, calculate_scroll_offset, render_help_bar};