v0.0.28: BotFather-only registration, per-instance bot toggle, docs update

Security:
- Bot registration restricted to BotFather (requires botfather_token)
- Direct POST /v1/bot/register without BotFather auth → rejected

Deploy:
- systemd service reads /home/warzone/server.env for EXTRA_ARGS
- deploy/warzone-server.env.mequ: no bots (default)
- deploy/warzone-server.env.kh3rad3ree: --enable-bots
- setup.sh copies per-hostname env file

Docs updated:
- LLM_HELP.md: BotFather flow, plaintext bot messaging, E2E option, bridge
- LLM_BOT_DEV.md: botfather_token requirement, E2E mode, bridge section
- BOT_API.md: full BotFather flow, ownership, numeric IDs, webhook delivery
- SERVER.md: --enable-bots flag, per-instance config, bot system section
- USAGE.md: bot messaging, BotFather, bridge tool

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

warzone/docs/SERVER.md

@@ -67,6 +67,7 @@ Rust 1.75 or later (`rust-version = "1.75"` in `Cargo.toml`).
 | `--bind` | `-b` | `0.0.0.0:7700` | Address and port to listen on |
 | `--data-dir` | `-d` | `./warzone-data` | Directory for the sled database |
 | `--federation` | `-f` | *(none)* | Path to federation JSON config file |
+| `--enable-bots` | | *(off)* | Enable Bot API and auto-create BotFather on startup |
 
 ### Environment Variables
 
@@ -75,6 +76,20 @@ Rust 1.75 or later (`rust-version = "1.75"` in `Cargo.toml`).
 | `RUST_LOG` | `warn` (production) | Log filter. Examples: `info`, `warzone_server=debug`, `trace` |
 | `WZP_RELAY_ADDR` | *(none)* | WZP voice relay address advertised to clients |
 
+### Per-Instance Configuration (`server.env`)
+
+Each server instance can use a `server.env` file for per-instance settings.
+Place it in the working directory or alongside the binary. This allows
+different instances to have different configurations (e.g., bots enabled on
+one server but not another).
+
+Example `server.env`:
+```
+RUST_LOG=info
+WZP_RELAY_ADDR=relay.example.com:3478
+ENABLE_BOTS=true
+```
+
 ### systemd Service
 
 A production-ready unit file is provided at `deploy/warzone-server.service`:
@@ -209,6 +224,42 @@ Returns JSON with connection state, peer info, and presence data.
 
 ---
 
+## 4b. Bot System
+
+### Enabling Bots
+
+Start the server with `--enable-bots` to activate bot functionality. Without
+this flag, all bot endpoints return 403.
+
+```bash
+./warzone-server --bind 0.0.0.0:7700 --enable-bots
+```
+
+### BotFather Auto-Creation
+
+On first start with `--enable-bots`, the server auto-creates the `@botfather`
+bot. The BotFather token is printed to the server logs. Users interact with
+`@botfather` to register new bots.
+
+### Per-Instance Bot Toggle
+
+Bot support can be enabled independently per server instance:
+
+| Instance | Bots | Config |
+|----------|------|--------|
+| mequ | Disabled | No `--enable-bots` flag |
+| kh3rad3ree | Enabled | `--enable-bots` flag set |
+
+### Bot Webhook Delivery
+
+When a bot has a webhook configured (via `setWebhook`), incoming messages are
+delivered live to the webhook URL via HTTP POST instead of being queued for
+`getUpdates` polling. This is integrated into the standard message routing
+pipeline -- `deliver_or_queue` checks for webhook configuration before
+queueing.
+
+---
+
 ## 5. API Reference
 
 All endpoints are prefixed with `/v1`. The web UI is served at `/`.