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/message_bubble.rs

@@ -8,6 +8,8 @@
 use crate::config::Config;
 use crate::formatting;
 use crate::tdlib::MessageInfo;
+#[cfg(feature = "images")]
+use crate::tdlib::PhotoDownloadState;
 use crate::types::MessageId;
 use crate::utils::{format_date, format_timestamp_with_tz};
 use ratatui::{
@@ -392,5 +394,75 @@ pub fn render_message_bubble(
         }
     }
 
+    // Отображаем статус фото (если есть)
+    #[cfg(feature = "images")]
+    if let Some(photo) = msg.photo_info() {
+        match &photo.download_state {
+            PhotoDownloadState::Downloading => {
+                let status = "📷 ⏳ Загрузка...";
+                if msg.is_outgoing() {
+                    let padding = content_width.saturating_sub(status.chars().count() + 1);
+                    lines.push(Line::from(vec![
+                        Span::raw(" ".repeat(padding)),
+                        Span::styled(status, Style::default().fg(Color::Yellow)),
+                    ]));
+                } else {
+                    lines.push(Line::from(Span::styled(
+                        status,
+                        Style::default().fg(Color::Yellow),
+                    )));
+                }
+            }
+            PhotoDownloadState::Error(e) => {
+                let status = format!("📷 [Ошибка: {}]", e);
+                if msg.is_outgoing() {
+                    let padding = content_width.saturating_sub(status.chars().count() + 1);
+                    lines.push(Line::from(vec![
+                        Span::raw(" ".repeat(padding)),
+                        Span::styled(status, Style::default().fg(Color::Red)),
+                    ]));
+                } else {
+                    lines.push(Line::from(Span::styled(
+                        status,
+                        Style::default().fg(Color::Red),
+                    )));
+                }
+            }
+            PhotoDownloadState::Downloaded(_) if photo.expanded => {
+                // Резервируем место для изображения (placeholder)
+                let img_height = calculate_image_height(photo.width, photo.height, content_width);
+                for _ in 0..img_height {
+                    lines.push(Line::from(""));
+                }
+            }
+            _ => {
+                // NotDownloaded или Downloaded + !expanded — ничего не рендерим,
+                // текст сообщения уже содержит 📷 prefix
+            }
+        }
+    }
+
     lines
 }
+
+/// Информация для отложенного рендеринга изображения поверх placeholder
+#[cfg(feature = "images")]
+pub struct DeferredImageRender {
+    pub message_id: MessageId,
+    /// Смещение в строках от начала всего списка сообщений
+    pub line_offset: usize,
+    pub width: u16,
+    pub height: u16,
+}
+
+/// Вычисляет высоту изображения (в строках) с учётом пропорций
+#[cfg(feature = "images")]
+pub fn calculate_image_height(img_width: i32, img_height: i32, content_width: usize) -> u16 {
+    use crate::constants::{MAX_IMAGE_HEIGHT, MAX_IMAGE_WIDTH, MIN_IMAGE_HEIGHT};
+
+    let display_width = (content_width as u16).min(MAX_IMAGE_WIDTH);
+    let aspect = img_height as f64 / img_width as f64;
+    // Терминальные символы ~2:1 по высоте, компенсируем
+    let raw_height = (display_width as f64 * aspect * 0.5) as u16;
+    raw_height.clamp(MIN_IMAGE_HEIGHT, MAX_IMAGE_HEIGHT)
+}