feat(brand): BRAND_* env scheme — instance branding without a rebuild

Replace baked-in UOM/MysticMoon/UOMysticmoon branding with a BRAND_* env
scheme so one prebuilt image runs as any shard; UOMysticmoon becomes the
first tenant that sets these vars rather than a special case in the code.

Architecture (chosen because the app ships as a prebuilt image):
- server/src/config/brand.js + bot/src/brand.js read BRAND_* once at boot,
  with Runic Gateway defaults.
- Text/colors reach the SPA at RUNTIME through the existing public settings
  API (settings.model.getPublic -> SiteContext), so no client rebuild. The
  admin-editable site title + contact email still override BRAND_NAME/email.
- SiteContext applies BRAND_ACCENT_COLOR to the --accent CSS var at runtime.
- Express templates the built index.html <title>/description/OG/favicon at
  serve time from BRAND_* (renderIndexHtml in app.js).
- Server-side consumers read brand directly: emails, TOTP issuer, API docs,
  boot logs, HTML error page. Bot uses it for embed color + logs.

Assets: logo/hero/favicon delivered from a ./brand:/app/brand bind-mount
(BRAND_LOGO/HERO/FAVICON), with neutral defaults baked in; hero falls back
to a built-in image when unset.

Scope: also genericized package.json names (uomysticmoon-* -> runic-gateway-*)
and the DB_NAME/DB_USER/COOKIE_NAME code defaults (runic_gateway/runic/
rg_token). Production keeps its real values by pinning them in .env — see
.env.uomysticmoon.example, which reproduces the exact UOMysticmoon identity
(proof the substitution works). Changing a deployed COOKIE_NAME invalidates
existing sessions, so UOMysticmoon pins uomm_token.

Verified: 193 server tests pass, client builds, app.js loads + templates the
built index.html, brand transform injects title/description/OG/favicon.

README.md

@@ -1,7 +1,10 @@
-# UOMysticmoon Website
+# Runic Gateway Website
 
-Public site, wiki, and protected admin panel for the **UOMysticmoon** private Ultima Online
-shard — a full-stack app in one repo:
+Public site, wiki, and protected admin panel for a private Ultima Online shard — a
+full-stack app in one repo. Branding is instance-configurable via `BRAND_*` (see
+[Branding](#branding)); **UOMysticmoon** is the first instance.
+
+A full-stack app in one repo:
 
 - **Backend** — Node.js + Express REST API (layered `router → controller → model → db`), MariaDB, a provider-agnostic session layer (JWT cookie for web, bearer tokens for mobile, pluggable SSO).
 - **Frontend** — React + Vite single-page app (public site, wiki, and the admin panel), dark "gothic" theme (Cinzel + Georgia).
@@ -133,14 +136,14 @@ to the backend, so the SPA stays same-origin (cookies work).
 **1. Start a MariaDB the backend can reach** (published on `localhost:3306`):
 
 ```bash
-docker run -d --name uomm-db -p 3306:3306 -e MARIADB_DATABASE=uomysticmoon -e MARIADB_USER=uomm -e MARIADB_PASSWORD=devpass -e MARIADB_ROOT_PASSWORD=rootpass mariadb:11
+docker run -d --name rg-db -p 3306:3306 -e MARIADB_DATABASE=runic_gateway -e MARIADB_USER=runic -e MARIADB_PASSWORD=devpass -e MARIADB_ROOT_PASSWORD=rootpass mariadb:11
 ```
 
 **2. Configure + start the backend** (terminal 1):
 
 ```bash
 cp server/.env.example server/.env
-# Set DB_HOST=127.0.0.1, DB_PORT=3306, DB_USER=uomm, DB_PASSWORD=devpass,
+# Set DB_HOST=127.0.0.1, DB_PORT=3306, DB_USER=runic, DB_PASSWORD=devpass,
 #     JWT_SECRET=<anything>, ADMIN_USERNAME=admin, ADMIN_PASSWORD=<your password>
 npm run install-server
 npm run server          # nodemon → http://localhost:3000
@@ -249,7 +252,7 @@ actually returns (`400` validation, `401`/`403` auth, `404`, `409` conflicts, `4
 
 **Authentication in the UI** — click **Authorize** and provide either:
 
-- `cookieAuth` — the `uomm_token` session cookie (set automatically in the browser after
+- `cookieAuth` — the session cookie (name `rg_token`, configurable via `COOKIE_NAME`; set automatically in the browser after
   `POST /api/v1/auth/login`), or
 - `bearerAuth` — a mobile access token from `POST /api/v1/auth/mobile/login` (sent as
   `Authorization: Bearer <token>`).
@@ -348,19 +351,20 @@ Copy `.env.example` (Compose) or `server/.env.example` (local) and fill in. **`.
 | `PORT` | `3000` | server listens on `0.0.0.0:PORT` |
 | `UPLOAD_DIR` | `<server>/uploads` | where post images are written (`/app/uploads`, volume-mounted, in Compose) |
 | `DB_HOST` / `DB_PORT` | `db` / `3306` | `db` in Compose; `127.0.0.1` for local dev |
-| `DB_NAME` / `DB_USER` / `DB_PASSWORD` | `uomysticmoon` / `uomm` / — | app database credentials |
+| `DB_NAME` / `DB_USER` / `DB_PASSWORD` | `runic_gateway` / `runic` / — | app database credentials |
 | `DB_ROOT_PASSWORD` | — | MariaDB root (Compose only) |
 | `JWT_SECRET` | — | **required** — long random string; signs session, mobile, and SSO-flow tokens |
 | `JWT_EXPIRES_IN` | `1d` | web session token + cookie lifetime |
 | `COOKIE_SECURE` | `auto` | `auto` = Secure only over HTTPS (works on LAN HTTP + Pangolin HTTPS) |
-| `COOKIE_NAME` | `uomm_token` | |
+| `COOKIE_NAME` | `rg_token` | changing it on a live instance invalidates existing sessions |
+| `BRAND_*` | Runic Gateway | instance branding (name, tagline, colors, logo/hero/favicon) — see [Branding](#branding) |
 | `SECRET_ENC_KEY` | — | **required in prod** — key for AES-256-GCM encryption of stored OAuth client secrets. Dev falls back to a key derived from `JWT_SECRET` (with a warning) |
 | `APP_BASE_URL` | — | public base URL, used to build the SSO OAuth `redirect_uri` (`${APP_BASE_URL}/api/v1/auth/sso/:provider/callback`). Set in prod to match what you register with Google/Discord; if unset it is derived from the request (fine for local dev) |
 | `MOBILE_ACCESS_TTL` | `15m` | mobile bearer **access** token lifetime (short-lived) |
 | `MOBILE_REFRESH_TTL_DAYS` | `30` | mobile **refresh** token lifetime (long-lived, rotated on use) |
 | `TRUST_PROXY` | `1` | reverse-proxy trust for correct `req.ip` / `req.secure` (rate limiting, backoff, bot-ban). Pin to the proxy hop's LAN IP in prod. A blanket `true` is rejected (coerced to `1`) to block `X-Forwarded-For` spoofing |
 | `DEBUG_TRUST_PROXY` | `0` | `1` logs raw peer address + `X-Forwarded-For` + resolved `req.ip` per request (to verify/refresh the proxy IP). Noisy — leave off |
-| `TOTP_ISSUER` | `UOMysticmoon` | label shown in authenticator apps for optional per-user 2FA |
+| `TOTP_ISSUER` | `BRAND_NAME` | label shown in authenticator apps for optional per-user 2FA |
 | `TOTP_CHALLENGE_TTL` | `5m` | lifetime of the short-lived post-password "awaiting code" step |
 | `ADMIN_USERNAME` / `ADMIN_PASSWORD` | — | first-admin bootstrap (first boot only) |
 | _Email_ | — | configured in Admin → Settings → Email (Gmail OAuth2), not via env; recipient = `contact_email` setting |
@@ -372,6 +376,32 @@ Copy `.env.example` (Compose) or `server/.env.example` (local) and fill in. **`.
 
 ---
 
+## Branding
+
+Instance identity is data, not code — set via `BRAND_*` env vars, so one prebuilt
+image can run as any shard. With none set, everything renders as **Runic Gateway**.
+
+| Var | What |
+|---|---|
+| `BRAND_NAME` / `BRAND_SHORT_NAME` | display name (full / short-in-prose) |
+| `BRAND_TAGLINE` / `BRAND_DESCRIPTION` | tagline + meta/OG description |
+| `BRAND_CONTACT_EMAIL` / `BRAND_URL` | contact + canonical URL (for OG/absolute links) |
+| `BRAND_ACCENT_COLOR` | theme `--accent` (web) + Discord embed color |
+| `BRAND_LOGO` / `BRAND_HERO` / `BRAND_FAVICON` | image paths under the `/brand` mount, or absolute URLs |
+
+**How it flows:** text/colors reach the SPA at runtime through the public settings
+API (`SiteContext`), so no rebuild is needed; the server templates `index.html`
+`<title>`/meta/OG/favicon at boot; emails, TOTP issuer, and the Discord bot read
+`BRAND_*` directly. The admin-editable **site title** and **contact email**
+settings override `BRAND_NAME` / `BRAND_CONTACT_EMAIL` when set. Image assets are
+delivered from the `./brand` bind-mount (see `brand/README.md`).
+
+**UOMysticmoon** is the first instance — [`.env.uomysticmoon.example`](.env.uomysticmoon.example)
+holds the exact `BRAND_*` + infra (`DB_NAME`/`DB_USER`/`COOKIE_NAME`) pinning to
+run this repo as UOMysticmoon.
+
+---
+
 ## Security
 
 **Session & authorization**