feat: implement Phase 12 — voice message playback with ffplay

Add voice message playback infrastructure:
- AudioPlayer using ffplay subprocess with SIGSTOP/SIGCONT for pause/resume
- VoiceCache with LRU eviction (100 MB limit)
- TDLib integration: VoiceInfo, VoiceDownloadState, PlaybackState types
- download_voice_note() in TdClientTrait
- Keybindings: Space (play/pause), ←/→ (seek ±5s)
- Auto-stop playback on message navigation
- Remove debug_log module

src/input/handlers/chat.rs

@@ -68,9 +68,17 @@ pub async fn handle_message_selection<T: TdClientTrait>(app: &mut App<T>, _key:
                 }
             }
         }
-        #[cfg(feature = "images")]
         Some(crate::config::Command::ViewImage) => {
-            handle_view_image(app).await;
+            handle_view_or_play_media(app).await;
+        }
+        Some(crate::config::Command::TogglePlayback) => {
+            handle_toggle_voice_playback(app).await;
+        }
+        Some(crate::config::Command::SeekForward) => {
+            handle_voice_seek(app, 5.0);
+        }
+        Some(crate::config::Command::SeekBackward) => {
+            handle_voice_seek(app, -5.0);
         }
         Some(crate::config::Command::ReactMessage) => {
             let Some(msg) = app.get_selected_message() else {
@@ -467,6 +475,81 @@ pub async fn handle_open_chat_keyboard_input<T: TdClientTrait>(app: &mut App<T>,
     }
 }
 
+/// Обработка команды ViewImage — только фото
+async fn handle_view_or_play_media<T: TdClientTrait>(app: &mut App<T>) {
+    let Some(msg) = app.get_selected_message() else {
+        return;
+    };
+
+    if msg.has_photo() {
+        #[cfg(feature = "images")]
+        handle_view_image(app).await;
+        #[cfg(not(feature = "images"))]
+        {
+            app.status_message = Some("Просмотр изображений отключён".to_string());
+        }
+    } else {
+        app.status_message = Some("Сообщение не содержит фото".to_string());
+    }
+}
+
+/// Space: play/pause toggle для голосовых сообщений
+async fn handle_toggle_voice_playback<T: TdClientTrait>(app: &mut App<T>) {
+    use crate::tdlib::PlaybackStatus;
+
+    // Если уже есть активное воспроизведение — toggle pause/resume
+    if let Some(ref mut playback) = app.playback_state {
+        if let Some(ref player) = app.audio_player {
+            match playback.status {
+                PlaybackStatus::Playing => {
+                    player.pause();
+                    playback.status = PlaybackStatus::Paused;
+                    app.status_message = Some("⏸ Пауза".to_string());
+                }
+                PlaybackStatus::Paused => {
+                    player.resume();
+                    playback.status = PlaybackStatus::Playing;
+                    app.status_message = Some("▶ Воспроизведение".to_string());
+                }
+                _ => {}
+            }
+            app.needs_redraw = true;
+        }
+        return;
+    }
+
+    // Нет активного воспроизведения — пробуем запустить текущее голосовое
+    let Some(msg) = app.get_selected_message() else {
+        return;
+    };
+    if msg.has_voice() {
+        handle_play_voice(app).await;
+    }
+}
+
+/// Seek голосового сообщения на delta секунд
+fn handle_voice_seek<T: TdClientTrait>(app: &mut App<T>, delta: f32) {
+    use crate::tdlib::PlaybackStatus;
+    use std::time::Duration;
+
+    let Some(ref mut playback) = app.playback_state else {
+        return;
+    };
+    let Some(ref player) = app.audio_player else {
+        return;
+    };
+
+    if matches!(playback.status, PlaybackStatus::Playing | PlaybackStatus::Paused) {
+        let new_position = (playback.position + delta).clamp(0.0, playback.duration);
+        if player.seek(Duration::from_secs_f32(new_position)).is_ok() {
+            playback.position = new_position;
+            let arrow = if delta > 0.0 { "→" } else { "←" };
+            app.status_message = Some(format!("{} {:.0}s", arrow, new_position));
+            app.needs_redraw = true;
+        }
+    }
+}
+
 /// Обработка команды ViewImage — открыть модальное окно с фото
 #[cfg(feature = "images")]
 async fn handle_view_image<T: TdClientTrait>(app: &mut App<T>) {
@@ -510,6 +593,125 @@ async fn handle_view_image<T: TdClientTrait>(app: &mut App<T>) {
     }
 }
 
+/// Вспомогательная функция для воспроизведения из конкретного пути
+async fn handle_play_voice_from_path<T: TdClientTrait>(
+    app: &mut App<T>,
+    path: &str,
+    voice: &crate::tdlib::VoiceInfo,
+    msg: &crate::tdlib::MessageInfo,
+) {
+    use crate::tdlib::{PlaybackState, PlaybackStatus};
+
+    if let Some(ref player) = app.audio_player {
+        match player.play(path) {
+            Ok(_) => {
+                app.playback_state = Some(PlaybackState {
+                    message_id: msg.id(),
+                    status: PlaybackStatus::Playing,
+                    position: 0.0,
+                    duration: voice.duration as f32,
+                    volume: player.volume(),
+                });
+                app.status_message = Some(format!("▶ Воспроизведение ({:.0}s)", voice.duration));
+                app.needs_redraw = true;
+            }
+            Err(e) => {
+                app.error_message = Some(format!("Ошибка воспроизведения: {}", e));
+            }
+        }
+    } else {
+        app.error_message = Some("Аудиоплеер не инициализирован".to_string());
+    }
+}
+
+/// Воспроизведение голосового сообщения
+async fn handle_play_voice<T: TdClientTrait>(app: &mut App<T>) {
+    use crate::tdlib::VoiceDownloadState;
+
+    let Some(msg) = app.get_selected_message() else {
+        return;
+    };
+
+    if !msg.has_voice() {
+        return;
+    }
+
+    let voice = msg.voice_info().unwrap();
+    let file_id = voice.file_id;
+
+    match &voice.download_state {
+        VoiceDownloadState::Downloaded(path) => {
+            // TDLib может вернуть путь без расширения — ищем файл с .oga
+            use std::path::Path;
+            let audio_path = if Path::new(path).exists() {
+                path.clone()
+            } else {
+                // Пробуем добавить .oga
+                let with_oga = format!("{}.oga", path);
+                if Path::new(&with_oga).exists() {
+                    with_oga
+                } else {
+                    // Пробуем найти файл с похожим именем в той же папке
+                    if let Some(parent) = Path::new(path).parent() {
+                        if let Some(stem) = Path::new(path).file_name() {
+                            if let Ok(entries) = std::fs::read_dir(parent) {
+                                for entry in entries.flatten() {
+                                    let entry_name = entry.file_name();
+                                    if entry_name.to_string_lossy().starts_with(&stem.to_string_lossy().to_string()) {
+                                        return handle_play_voice_from_path(app, &entry.path().to_string_lossy(), &voice, &msg).await;
+                                    }
+                                }
+                            }
+                        }
+                    }
+                    app.error_message = Some(format!("Файл не найден: {}", path));
+                    return;
+                }
+            };
+
+            handle_play_voice_from_path(app, &audio_path, &voice, &msg).await;
+        }
+        VoiceDownloadState::Downloading => {
+            app.status_message = Some("Загрузка голосового...".to_string());
+        }
+        VoiceDownloadState::NotDownloaded => {
+            use crate::tdlib::{PlaybackState, PlaybackStatus};
+
+            // Начинаем загрузку
+            app.status_message = Some("Загрузка голосового...".to_string());
+            match app.td_client.download_voice_note(file_id).await {
+                Ok(path) => {
+                    // Пытаемся воспроизвести после загрузки
+                    if let Some(ref player) = app.audio_player {
+                        match player.play(&path) {
+                            Ok(_) => {
+                                app.playback_state = Some(PlaybackState {
+                                    message_id: msg.id(),
+                                    status: PlaybackStatus::Playing,
+                                    position: 0.0,
+                                    duration: voice.duration as f32,
+                                    volume: player.volume(),
+                                });
+                                app.status_message = Some(format!("▶ Воспроизведение ({:.0}s)", voice.duration));
+                                app.needs_redraw = true;
+                            }
+                            Err(e) => {
+                                app.error_message = Some(format!("Ошибка воспроизведения: {}", e));
+                            }
+                        }
+                    }
+                }
+                Err(e) => {
+                    app.error_message = Some(format!("Ошибка загрузки: {}", e));
+                }
+            }
+        }
+        VoiceDownloadState::Error(e) => {
+            app.error_message = Some(format!("Ошибка загрузки: {}", e));
+        }
+    }
+}
+
 // TODO (Этап 4): Эти функции будут переписаны для модального просмотрщика
 /*
 #[cfg(feature = "images")]
@@ -529,4 +731,5 @@ fn expand_photo<T: TdClientTrait>(app: &mut App<T>, msg_id: crate::types::Messag
 async fn _download_and_expand<T: TdClientTrait>(app: &mut App<T>, msg_id: crate::types::MessageId, file_id: i32) {
     // Закомментировано - будет реализовано в Этапе 4
 }
-*/
+*/
+