refactor: implement trait-based DI for TdClient and fix stack overflow

Implement complete trait-based dependency injection pattern for TdClient
to enable testing with FakeTdClient mock. Fix critical stack overflow bugs
caused by infinite recursion in trait implementations.

Breaking Changes:
- App is now generic: App<T: TdClientTrait = TdClient>
- All UI and input handlers are generic over TdClientTrait
- TdClient methods now accessed through trait interface

New Files:
- src/tdlib/trait.rs: TdClientTrait definition with 40+ methods
- src/tdlib/client_impl.rs: TdClientTrait impl for TdClient
- tests/helpers/fake_tdclient_impl.rs: TdClientTrait impl for FakeTdClient

Critical Fixes:
- Fix stack overflow in send_message, edit_message, delete_messages
- Fix stack overflow in forward_messages, current_chat_messages
- Fix stack overflow in current_pinned_message
- All methods now call message_manager directly to avoid recursion

Testing:
- FakeTdClient supports configurable auth_state for auth screen tests
- Added pinned message support in FakeTdClient
- All 196+ tests passing (188 tests + 8 benchmarks)

Dependencies:
- Added async-trait = "0.1"

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/input/handlers/global.rs

@@ -7,6 +7,7 @@
 //! - Ctrl+F: Search messages in chat
 
 use crate::app::App;
+use crate::tdlib::TdClientTrait;
 use crate::types::ChatId;
 use crate::utils::{with_timeout, with_timeout_msg};
 use crossterm::event::{KeyCode, KeyEvent, KeyModifiers};
@@ -17,7 +18,7 @@ use std::time::Duration;
 /// # Returns
 ///
 /// `true` если команда была обработана, `false` если нет
-pub async fn handle_global_commands(app: &mut App, key: KeyEvent) -> bool {
+pub async fn handle_global_commands<T: TdClientTrait>(app: &mut App<T>, key: KeyEvent) -> bool {
     let has_ctrl = key.modifiers.contains(KeyModifiers::CONTROL);
 
     match key.code {
@@ -55,7 +56,7 @@ pub async fn handle_global_commands(app: &mut App, key: KeyEvent) -> bool {
 }
 
 /// Обрабатывает загрузку и отображение закреплённых сообщений
-async fn handle_pinned_messages(app: &mut App) {
+async fn handle_pinned_messages<T: TdClientTrait>(app: &mut App<T>) {
     if app.selected_chat_id.is_some() && !app.is_pinned_mode() {
         if let Some(chat_id) = app.get_selected_chat_id() {
             app.status_message = Some("Загрузка закреплённых...".to_string());