feat(telegram): split connector into home validator + remote bot

Move all Telegram egress off the main host. The single connector held the
bot token, long-polled Telegram and answered the gateway/backend over the
trusted internal network, so the whole component (including login validation)
shared fate with its VPN sidecar. Split it into two binaries that share the
token:

- cmd/validator (home, no VPN): Mini App initData + Login Widget HMAC only,
  never calls the Bot API. The gateway dials it for Telegram auth, so game
  login is now independent of Telegram reachability.
- cmd/bot (remote): Bot API long-poll + sendMessage, the only component
  reaching Telegram. It holds no inbound port — it dials the gateway over a
  new reverse mTLS bot-link (pkg/proto/botlink/v1) and executes the send
  commands the gateway pushes.

The gateway funnels sends to the bot-link: out-of-app push is fire-and-forget
(at-most-once, dropped if no bot is connected); the backend admin broadcasts
reach a gateway-served relay that forwards them and awaits the bot's ack
(SendToUser/SendToGameChannel contract preserved). mTLS (pkg/mtls) is the one
inter-service link that leaves the trusted segment; validator<->gateway and
the relay stay plaintext internal. The bot is Telegram-rate-limited.

One bot now; the gateway bot registry, an owns_updates flag and per-command
ids leave seams for N later. Webhook rejected (one URL per token, adds inbound
+ a static address).

The unified test contour runs the split (the bot keeps its VPN sidecar and
dials the gateway by its internal name; bot-link certs from deploy/gen-certs.sh,
generated in CI). The prod wiring — the bot on a separate host (no VPN), the
gateway bot-link port published, PROD_ certs with scheduled rotation, an SSH
deploy of both hosts together — is the deferred final stage (PRERELEASE.md TX,
Stage 18).

Docs: ARCHITECTURE, PRERELEASE (phase TX), platform/telegram + gateway +
backend + deploy READMEs, FUNCTIONAL(+ru), CLAUDE.md, .env.example.

deploy/.env.example

@@ -38,8 +38,12 @@ VITE_GATEWAY_URL=
 GRAFANA_ROOT_URL=/_gm/grafana/         # set the full https URL behind a real domain
 GRAFANA_ADMIN_PASSWORD=admin
 
-# --- Telegram connector -----------------------------------------------------
-AWG_CONF=                              # required; AmneziaWG sidecar config
+# --- Telegram validator + bot -----------------------------------------------
+# The token is shared: the validator uses it as the HMAC secret, the bot for the
+# Bot API. The bot-link wiring (validator/relay/mTLS addresses) is hard-wired in
+# docker-compose.yml; the mTLS material is NOT here — run `deploy/gen-certs.sh`
+# (writes deploy/certs/, gitignored) before `docker compose up`.
+AWG_CONF=                              # required; AmneziaWG sidecar config (the bot's Telegram egress)
 TELEGRAM_BOT_TOKEN=                    # required
 TELEGRAM_GAME_CHANNEL_ID=
 TELEGRAM_MINIAPP_URL=                  # required