refactor: remove enqueueUpload from ITelegramService and BotPool

Per-bot queue replaces global upload queue — BotPool handles
queueing internally.

- Remove enqueueUpload method signature from ITelegramService interface
- Remove enqueueUpload method from BotPool class
- Remove import of enqueueUpload from upload-queue module
- Refactor forwardToStorage to call executeWithBotRetry directly
  instead of wrapping via enqueueUpload
- Fix trailing blank lines flagged by Biome formatter

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/domain/ports/telegram-service.ts

@@ -50,15 +50,4 @@ export interface ITelegramService {
    * @returns Metadata including size, MIME type, download path, and bot token.
    */
   getFileInfo(telegramFileId: string): Promise<TelegramFileInfo>;
-
-  /**
-   * Enqueue a task for sequential upload execution.
-   *
-   * Ensures only one Telegram upload runs at a time to avoid
-   * rate limits and resource contention.
-   *
-   * @param task - An async function performing the upload.
-   * @returns The result of the task.
-   */
-  enqueueUpload<T>(task: () => Promise<T>): Promise<T>;
 }