feat(transcribe,texts): voice notes and round videos to the bot come with a transcript, beavergram finds them by sha256 and telegram premium transcribes

README.md

@@ -165,6 +165,11 @@ pieces live in `beaver_agent/`, one concern per module:
   files for deep chats, `/api`, `/admin`, `/anthropic`, `/mcp`
 - `texts.py` - everything the gateway says to the model or to the user,
   in Russian (the gateway's own defaults are English)
+- `transcribe.py` - voice notes and round videos sent to the bot get a
+  transcript under the attachment note: the file's sha256 finds the same
+  message in beavergram (the owner's account sees it too), and Telegram
+  Premium transcribes it there; needs `BEAVERGRAM_MCP` with its `token` and
+  `TELEGRAM_USER_ID`, music and audio files are left alone
 - `memory/` - the recall block under a message, the reply log, handouts
   and seeds, the vault watcher, the curator briefing
 - `jobs/` - crons and webhooks, one file per job