Add admin bot HTTP API for managing private games (#4388)

## What

A trusted, server-side HTTP API so a bot authenticated with a shared
secret can **create private games, change their settings, start them,
kick players, and pause/resume** — without opening a WebSocket or
joining as a player.

Two endpoints under `/api/adminbot/`, reaching the owning worker via the
existing `/wN/` nginx routing. They reuse the existing Zod schemas and
`GameServer` methods, mirroring the WebSocket intent flow rather than
inventing a new wire protocol.

| Endpoint | Purpose |
| --- | --- |
| `POST /api/adminbot/create_game` | Create a private game; the worker
mints a self-owned id and returns it (body:
`GameConfigSchema.partial()`) |
| `POST /api/adminbot/game/:id/intent` | Send a lobby-management intent
(body: base `IntentSchema`) |

## How it works

- **Auth:** `ADMIN_BOT_API_KEY` env var via the `x-admin-bot-key` header
(timing-safe compare). The whole API is **disabled — 404 — when the var
is unset**, so non-configured environments expose nothing. It's distinct
from the per-instance `ADMIN_TOKEN`, which an external bot can't know.
- **`GameServer.handleIntent`** is the unified intent dispatch for both
the WebSocket `case "intent"` path and the admin-bot HTTP API. An
`IntentActor` carries identity + authority (per-connection
lobby-creator/role checks for the WS path; admin authority for the bot).
It honors `update_game_config`, `toggle_game_start_timer`,
`kick_player`, and `toggle_pause` — **on private games only**
(`isPublic()` → 403). Gameplay intents and `mark_disconnected` are
rejected (400).
- **Private games only.** `create_game` rejects any `gameType` other
than `Private` (Public *and* Singleplayer → 400); an omitted `gameType`
defaults to `Private`.
- **The bot is never a player.** It sends no `clientID`; the server
stamps a placeholder `ADMIN_BOT_CLIENT_ID = "ADMINBOT"` (collision-proof
— contains `I`/`O`, which `generateID()` never emits). A gameplay intent
stamped with it would resolve to no player, so puppeteering is
structurally impossible on top of the explicit 400.
- **Determinism unchanged:** the only intent that reaches the sim is
`toggle_pause`, via the same `addIntent` → turn queue →
`ServerTurnMessage` path the WS uses.

## Notable details for review

- **`hostCheats` is assigned unconditionally — on purpose.**
`updateGameConfig` sets `this.gameConfig.hostCheats =
gameConfig.hostCheats` unconditionally, unlike its sibling fields (which
are guarded on `!== undefined`). The WS host clears cheats by re-sending
the *full* config with `hostCheats: undefined`, so here `undefined` must
mean "clear", not "leave unchanged". **Caveat for the admin bot**, which
is a *partial*-update client: a partial `update_game_config` that omits
`hostCheats` will clear it — the bot should send `hostCheats` explicitly
(or a full config) when it wants to keep a previously-set value.
- **Deploy wiring:** `ADMIN_BOT_API_KEY` is piped through the deploy
steps' `env:` in `deploy.yml`/`release.yml` → `deploy.sh` heredoc →
container via `update.sh`'s `--env-file`. The remaining manual step is
creating the GitHub secret itself.

## Tests

19 new tests:
- `GameServer.handleIntent` admin-bot behavior (per-intent,
private-only, post-start guards, placeholder clientID, rejected
gameplay/`mark_disconnected` intents).
- `create_game` gameType guard (Public and Singleplayer both rejected).
- `requireAdminBotKey` middleware (404 disabled / 401 missing / 401
wrong / pass).

tsc + eslint clean.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

package.json

@@ -5,7 +5,7 @@
     "build-prod": "concurrently --kill-others-on-fail \"tsc --noEmit\" \"vite build\"",
     "start:client": "vite",
     "start:server": "tsx src/server/Server.ts",
-    "start:server-dev": "cross-env GAME_ENV=dev NUM_WORKERS=2 TURNSTILE_SITE_KEY=1x00000000000000000000AA API_KEY=WARNING_DEV_API_KEY_DO_NOT_USE_IN_PRODUCTION DOMAIN=localhost GIT_COMMIT=DEV tsx src/server/Server.ts",
+    "start:server-dev": "cross-env GAME_ENV=dev NUM_WORKERS=2 TURNSTILE_SITE_KEY=1x00000000000000000000AA API_KEY=WARNING_DEV_API_KEY_DO_NOT_USE_IN_PRODUCTION ADMIN_BOT_API_KEY=WARNING_DEV_ADMIN_BOT_KEY_DO_NOT_USE_IN_PRODUCTION DOMAIN=localhost GIT_COMMIT=DEV tsx src/server/Server.ts",
     "dev": "cross-env GAME_ENV=dev concurrently \"npm run start:client\" \"npm run start:server-dev\"",
     "dev:host": "cross-env GAME_ENV=dev VITE_HOST=lan concurrently \"npm run start:client\" \"npm run start:server-dev\"",
     "dev:staging": "cross-env GAME_ENV=dev API_DOMAIN=api.openfront.dev concurrently \"npm run start:client\" \"npm run start:server-dev\"",