feat(rust): identity — a link code from the game, and the Steam id inside core's user page

R1's identity link, site-side, and R13's first extension slot. A player types
/link in game, the plugin hands them a six-character code privately, and they
enter it here; the site records who owns which Steam account, and an operator
sees that on core's own `/admin/users/:id` page.

**The site is the author of record and the game holds nothing.** There is no
per-account store in Rust that survives a wipe, and phase 7 needs the site
authoritative anyway — it pushes permissions INTO the game keyed by Steam id. A
copy in the game would be a second thing to reconcile every wipe, for no question
it could answer better.

## D24 — a code is minted by ONE server, so every server is asked

Nothing in six characters says where it came from. The fleet is asked in turn and
the first `link.ok` wins; the others answer `unknown` and nothing happens there,
because a code is only spent at the server that actually holds it. Asking the
player to pick was rejected: a wrong pick would come back indistinguishable from
a wrong code, and that is the one refusal which must not be ambiguous.

**"Every reachable server refused" is not the same answer as "a server was
unreachable."** Collapsing them tells a player whose server is down that their
code is wrong — so they run /link again on that same server and are told the same
thing for as long as it stays down. `unsure` is that case, and it says to try
again rather than to fetch a new code.

## D23 — a Steam id another account holds is refused, never moved

The primary key is `steam_id`, and it is load-bearing rather than tidy: phase 7
grants permissions against a link and phase 13 hangs entitlements off it, so a
silent move is an account takeover performed by typing six characters. The
refusal names the holder, because the advice is unusable without it. The INSERT
is a plain INSERT for the same reason — `ON DUPLICATE KEY UPDATE` here would BE
that move — and the duplicate-key error is the refusal for the race the check
above cannot close.

The way out is `/unlink` in game, which reaches the site off the ingest feed
rather than through a route (the plugin has no link to delete). D25 adds the
other way out: staff can sever a link from the admin panel, for a player who
cannot reach that Steam account in game.

## The slot, and the hole it found in this repo's own generator

`admin.users.detail` is declared in `module.json` AND registered in `index.js`
AND filled by the chunk — three places, because the server half and the client
half are different registrations that share one name.

`swaggerFragment.js` knew only about tier routers, so the two routes under
`/admin/users/:id` were generated by nothing: a fragment that was internally
consistent and described two routes fewer than the module serves. A slot's mount
is core's and cannot be derived here, so it is a fourth constant beside
`TIER_BASE` — held to account by the frozen-manifest job, which was verified to
catch exactly this by removing the two paths and watching it fail.

## Smaller things worth knowing

- **Core's `useAsync` has no `refresh`.** A counter in the deps is how a page
  re-reads after its own write; it blanks while it re-reads, which is right here
  and is exactly what made it wrong for a poll.
- **Every player-portal nav row needs an `icon`** — core draws one on every row,
  and the client suite says so. This module had no icons file until now, because
  the public header is text buttons.
- The two new frame kinds are STAFF-only. Neither carries a code, but both name a
  Steam id beside a website account's activity, and that join is not a public
  fact about what happened on a server.
- The link code route carries its own rate limiter rather than core's
  `accountChangeLimiter`: this is guessing somebody else's secret, not changing
  your own password, and a shared counter would let one policy set the other.

Protocol 3 on all three declaration sites; 17 new tests, 136 green.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PMH6bw1jXMgbyF3ZWGEzSM

client/src/api.js

@@ -74,6 +74,20 @@ export const playerServers = {
   list: () => req('/player/rust/servers'),
 }
 
+// R1's identity link, from the signed-in player's side.
+//
+// **The code is the whole of what goes up.** The site has no idea which server
+// minted it — nothing in six characters says — so the server half asks each
+// configured server in turn (D24). A page that asked the player to pick would be
+// asking them a question the site can answer itself, and a wrong pick would come
+// back indistinguishable from a wrong code.
+export const playerLinks = {
+  list: () => req('/player/rust/links'),
+  confirm: (code) => req('/player/rust/link', { method: 'POST', body: { code } }),
+  remove: (steamId) =>
+    req(`/player/rust/links/${encodeURIComponent(steamId)}`, { method: 'DELETE' }),
+}
+
 // ── admin ─────────────────────────────────────────────────────────────────
 // **`sidecarToken` goes up and never comes back.** The list answers `hasToken`,
 // and a save that omits the field leaves the stored credential alone — so an
@@ -89,8 +103,23 @@ export const admin = {
     req(`/admin/rust/servers/${encodeURIComponent(id)}/test`, { method: 'POST' }),
 }
 
+// ── the admin.users.detail extension slot ─────────────────────────────────
+//
+// The client half of R13's first slot. Core hands the component a `userId` and
+// NOTHING else — not a client — so an extension builds its own bindings for the
+// routes it registered at the other end (§3.5). These two are the only calls in
+// this file whose path is core's rather than this module's: the resource is
+// core's user, and the module's own segment is the part after it.
+export const adminUserLinks = {
+  list: (userId) => req(`/admin/users/${encodeURIComponent(userId)}/rust/links`),
+  remove: (userId, steamId) =>
+    req(`/admin/users/${encodeURIComponent(userId)}/rust/links/${encodeURIComponent(steamId)}`, {
+      method: 'DELETE',
+    }),
+}
+
 // Exported for the rare caller that needs the base itself — an `<img src>`, a
 // download link, an EventSource. Reach for `request` first.
 export { BASE, query }
 
-export default { servers, playerServers, admin, BASE }
+export default { servers, playerServers, playerLinks, admin, adminUserLinks, BASE }

client/src/entry.jsx

@@ -20,7 +20,10 @@ import { registry, coreApiVersion } from './core.js'
 
 import Servers from './routes/public/Servers.jsx'
 import ServerDetail from './routes/public/ServerDetail.jsx'
+import Account from './routes/player/Account.jsx'
+import UserRustSections from './routes/admin/UserRustSections.jsx'
 import FooterStatus from './components/FooterStatus.jsx'
+import { IconLink } from './icons.jsx'
 
 // The module id, exactly as `module.json` spells it. Core keys the registry by it
 // and prefixes every route path with it.
@@ -54,11 +57,18 @@ const ID = 'rust'
 //
 // React Router ranks a static segment above a dynamic one, so `/rust` wins
 // against core's `/:slug` CMS route without depending on registration order.
+//
+// The player route is registered with an empty path for the same reason the
+// public list is: `/player/rust` is the whole of what this module asks a player
+// to do, and a landing page above one page is a page nobody wants. Core applies
+// its own portal chrome and its own auth gate to the tier, so the component
+// renders no layout and re-implements no check.
 registry.registerRoutes(ID, {
   public: [
     { path: '', element: <Servers /> },
     { path: 'servers/:id', element: <ServerDetail /> },
   ],
+  player: [{ path: '', element: <Account /> }],
 })
 
 // ── Nav ───────────────────────────────────────────────────────────────────
@@ -83,6 +93,18 @@ registry.registerNav(ID, {
   items: [{ label: 'Servers', to: '/rust' }],
 })
 
+// The player portal's row. It carries an `icon` because core draws one on every
+// portal row — a row without one is the only text in a column of glyphs, and
+// core used to render `<n.icon />` unguarded, which blanked the whole portal.
+//
+// No `order`: an unordered row appends after core's own rather than claiming a
+// position it was not given. Account, appeals and notifications are what a player
+// came to the portal for; linking a game account is what they do once.
+registry.registerNav(ID, {
+  area: 'player',
+  items: [{ label: 'Rust', to: '/player/rust', icon: IconLink }],
+})
+
 // ── Extension slots ───────────────────────────────────────────────────────
 //
 // Core declares a slot, only core may declare one, and at most one module may
@@ -97,6 +119,16 @@ registry.registerNav(ID, {
 // purpose.
 registry.registerExtension(ID, 'site.footer.status', FooterStatus)
 
+// R13's other slot, and the one that IS named in `module.json` — because it has
+// a server half too (`server/router/admin/usersRust.router.js`). The two halves
+// carry one name on purpose: a module that adds routes under
+// `/api/v1/admin/users/:id` is the module with something to show on that page.
+//
+// Core passes `userId` and nothing else, so the component builds its own client
+// for the routes the server half registered. It renders NOTHING for a user with
+// no linked Steam account, which is most of them.
+registry.registerExtension(ID, 'admin.users.detail', UserRustSections)
+
 // `module.json`'s `coreApi` range was checked by the loader before this file was
 // ever served, so there is nothing to re-check here. Log it anyway: a mismatch
 // between the core that validated the manifest and the core that published this

client/src/icons.jsx

@@ -0,0 +1,49 @@
+// ── The nav glyph for this module's player-portal row ─────────────────────
+//
+// `icon` is part of the nav-item contract (MODULE_API.md §3.3, 1.3.0): core
+// renders whatever component a row carries, exactly as it renders its own rows'
+// icons — and core's player portal draws a glyph on every row, so a row without
+// one reads as breakage rather than as a design. The client suite asserts it.
+//
+// The public header is text buttons and carries no icons, which is why this file
+// arrives with the player row and not before it.
+//
+// **The frame is copied from core's `PlayerPortalLayout`, deliberately and by
+// copy rather than by import** — 16px, `currentColor`, stroke 2. Four attributes
+// of presentation are not a component: putting them in the shared kit would
+// freeze core's icon sizing into the contract, where changing it later would be a
+// major bump. A module that wants to look like the nav it is in matches that nav.
+
+const Icon = ({ children }) => (
+  <svg
+    width="16"
+    height="16"
+    viewBox="0 0 24 24"
+    fill="none"
+    stroke="currentColor"
+    strokeWidth="2"
+    strokeLinecap="round"
+    strokeLinejoin="round"
+    aria-hidden="true"
+    focusable="false"
+  >
+    {children}
+  </svg>
+)
+
+/**
+ * A chain link — what the row is for.
+ *
+ * Not a gem, a person or a server: the portal's rows say what a player does
+ * there, and what a player does at `/player/rust` is link an account. Core's own
+ * neighbours are a gear (account), a shield (appeals) and a bell (notifications),
+ * so the row has to read as a verb in that company.
+ */
+export const IconLink = () => (
+  <Icon>
+    <path d="M10 13a5 5 0 007.07 0l2.83-2.83a5 5 0 00-7.07-7.07L11.5 4.5" />
+    <path d="M14 11a5 5 0 00-7.07 0L4.1 13.83a5 5 0 007.07 7.07L12.5 19.5" />
+  </Icon>
+)
+
+export default { IconLink }

client/src/routes/admin/UserRustSections.jsx

@@ -0,0 +1,147 @@
+// ── This module's fill for `admin.users.detail` ───────────────────────────
+//
+// R13's first slot, and the phase criterion as an operator meets it: the Steam
+// id inside core's own user page, under core's own security panel.
+//
+// **The slot hands over `userId` and nothing else** — not a client. So this file
+// builds its own bindings for the routes the server half registered
+// (`api.adminUserLinks`), which is §3.5's rule applied to a slot: the two ends of
+// a call belong to the same module even when the URL between them is core's.
+//
+// **Most users have no Rust account, so most of the time this renders nothing.**
+// A panel that announced "no linked Steam accounts" on every user page in a
+// community that also runs a UO shard would be noise on the overwhelming
+// majority of them. Silence is the honest answer to "what does the Rust module
+// know about this person" when it is nothing.
+
+import { useCallback, useState } from 'react'
+import { ago, count, duration } from '../../lib/format.js'
+import { useAsync } from '../../core.js'
+import api from '../../api.js'
+
+/** Six lines of furniture the §3.4 kit does not carry, so it is vendored. */
+function SectionTitle({ children }) {
+  return (
+    <div className="field-label" style={{ marginBottom: 12, marginTop: 4 }}>
+      {children}
+    </div>
+  )
+}
+
+/** One server's all-time totals for this player. */
+function ServerRow({ server }) {
+  return (
+    <li
+      className="sans"
+      style={{ display: 'flex', justifyContent: 'space-between', gap: 12, fontSize: '0.86rem', color: 'var(--ink)' }}
+    >
+      <span style={{ minWidth: 0, color: 'var(--head)' }}>{server.serverName}</span>
+      <span className="dim" style={{ flex: 'none', fontSize: '0.8rem' }}>
+        {count(server.kills)} kills · {count(server.deaths)} deaths · {duration(server.playtimeSec)}
+        {server.wipes > 1 ? ` · ${server.wipes} wipes` : ''}
+      </span>
+    </li>
+  )
+}
+
+/** One linked Steam account: who it is, when it was linked, and the way out. */
+function LinkPanel({ userId, link, onRemoved }) {
+  const [busy, setBusy] = useState(false)
+  const [error, setError] = useState('')
+
+  async function unlink() {
+    setBusy(true)
+    setError('')
+    try {
+      await api.adminUserLinks.remove(userId, link.steamId)
+      await onRemoved()
+    } catch (err) {
+      setError(err.message || 'Could not unlink that account.')
+      setBusy(false)
+    }
+  }
+
+  return (
+    <div className="panel" style={{ padding: '14px 16px' }}>
+      <div style={{ display: 'flex', alignItems: 'flex-start', gap: 14 }}>
+        <div style={{ minWidth: 0, flex: 1 }}>
+          <div className="display" style={{ fontSize: '1rem', color: 'var(--head)' }}>
+            {link.name || link.steamId}
+          </div>
+          <div className="sans dim" style={{ fontSize: '0.76rem', marginTop: 2 }}>
+            {link.steamId} · linked {ago(link.linkedAt)}
+            {link.serverId ? ` on ${link.serverId}` : ''}
+            {link.lastSeen ? ` · last played ${ago(link.lastSeen)}` : ' · never played'}
+          </div>
+          {/* Worth showing only when they differ: the name on the link is what
+              they were called when they linked, the other is what the game last
+              saw. A rename is the ordinary reason, and an operator reading a
+              support ticket wants both names. */}
+          {link.linkedName && link.name && link.linkedName !== link.name && (
+            <div className="sans dim" style={{ fontSize: '0.72rem', marginTop: 2 }}>
+              Linked as “{link.linkedName}”.
+            </div>
+          )}
+        </div>
+        <button type="button" className="btn ghost" onClick={unlink} disabled={busy} style={{ flex: 'none' }}>
+          {busy ? 'Unlinking…' : 'Unlink'}
+        </button>
+      </div>
+
+      {error && (
+        <p className="sans" style={{ color: '#e05a5a', fontSize: '0.8rem', margin: '8px 0 0' }}>{error}</p>
+      )}
+
+      {link.servers.length > 0 && (
+        <ul
+          style={{
+            listStyle: 'none',
+            margin: '12px 0 0',
+            padding: '12px 0 0',
+            borderTop: '1px solid var(--line-soft)',
+            display: 'flex',
+            flexDirection: 'column',
+            gap: 6,
+          }}
+        >
+          {link.servers.map((server) => (
+            <ServerRow key={server.serverId} server={server} />
+          ))}
+        </ul>
+      )}
+    </div>
+  )
+}
+
+export default function UserRustSections({ userId }) {
+  // Core's `useAsync` has no refresh, so a counter in the deps is how this
+  // re-reads after its own write (the same shape the player page uses).
+  const [reloads, setReloads] = useState(0)
+  const { data } = useAsync(() => api.adminUserLinks.list(userId), [userId, reloads])
+  const reload = useCallback(() => setReloads((n) => n + 1), [])
+
+  // No `Loading` and no `ErrorState`, deliberately. This is a section inside
+  // somebody else's page: a spinner on every user page for a module most users
+  // have nothing to do with is worse than a section that appears when it has
+  // something, and a failure here must not replace core's own user detail with an
+  // error card.
+  if (!data || data.links.length === 0) return null
+
+  return (
+    <section style={{ borderTop: '1px solid var(--line-soft)', marginTop: 30, paddingTop: 22 }}>
+      <SectionTitle>Rust</SectionTitle>
+
+      <div style={{ display: 'flex', flexDirection: 'column', gap: 12 }}>
+        {data.links.map((link) => (
+          <LinkPanel key={link.steamId} userId={userId} link={link} onRemoved={reload} />
+        ))}
+      </div>
+
+      <p className="sans dim" style={{ fontSize: '0.74rem', margin: '12px 0 0' }}>
+        A link is fleet-wide and totals are all-time, summed across every wipe. Unlinking here is
+        recorded in the activity log — it is the way back for a player who linked the wrong account
+        and cannot reach it in game.
+      </p>
+    </section>
+  )
+}

client/src/routes/player/Account.jsx

@@ -0,0 +1,191 @@
+// ── The player's own Rust identity ────────────────────────────────────────
+//
+// `/player/rust` — where a signed-in player links the Steam account they play
+// on. It is the one page in this module a player is asked to *do* something on,
+// and the thing they are doing matters more than it looks: from phase 7 the link
+// is what in-game permissions are granted against, and from phase 13 it is what
+// rewards are handed to.
+//
+// **A player route renders no layout of its own.** Core wraps `/player/*` in its
+// own portal chrome, so this page starts at a heading — unlike the public pages
+// in this module, which render `PublicLayout` themselves.
+//
+// The three-step instruction at the top is not decoration. Nothing else on the
+// site tells a player that the code comes from the game, and a code field with no
+// explanation is a code field nobody can use.
+
+import { useCallback, useState } from 'react'
+import { ErrorState, Loading, useAsync } from '../../core.js'
+import { ago, shortId } from '../../lib/format.js'
+import api from '../../api.js'
+
+/** The code field, and the four answers it can produce. */
+function LinkForm({ onLinked }) {
+  const [code, setCode] = useState('')
+  const [busy, setBusy] = useState(false)
+  const [message, setMessage] = useState('')
+  const [error, setError] = useState('')
+
+  async function submit(event) {
+    event.preventDefault()
+    if (!code.trim() || busy) return
+
+    setBusy(true)
+    setMessage('')
+    setError('')
+
+    try {
+      const result = await api.playerLinks.confirm(code.trim())
+      setMessage(
+        result.already
+          ? 'That account was already linked to you.'
+          : `Linked ${result.link.name || shortId(result.link.steamId)}.`,
+      )
+      setCode('')
+      await onLinked()
+    } catch (err) {
+      // Every refusal the server sends is already a sentence aimed at a player —
+      // "run /link again", "run /unlink in game", "try again in a minute" — so
+      // this renders it rather than replacing it with one of its own. The three
+      // are not interchangeable, and a page that flattened them into "could not
+      // link that code" would send a player back to the server that is down.
+      setError(err.message || 'Could not link that code.')
+    } finally {
+      setBusy(false)
+    }
+  }
+
+  return (
+    <form onSubmit={submit} style={{ marginTop: 18 }}>
+      <div style={{ display: 'flex', gap: 10, alignItems: 'flex-end', flexWrap: 'wrap' }}>
+        <label style={{ display: 'block' }}>
+          <span className="field-label" style={{ display: 'block', marginBottom: 6 }}>Link code</span>
+          <input
+            value={code}
+            onChange={(e) => setCode(e.target.value.toUpperCase())}
+            placeholder="K7M2PQ"
+            // The plugin's alphabet has no O, 0, I or 1, so a player reading a
+            // code off their screen cannot produce one — but they can type a
+            // lowercase one, and the code is matched case-insensitively at the
+            // other end. Upper-casing here makes what they typed look like what
+            // they were shown.
+            maxLength={12}
+            autoComplete="off"
+            spellCheck={false}
+            className="input"
+            style={{ textTransform: 'uppercase', letterSpacing: '0.18em', width: 160 }}
+          />
+        </label>
+        <button type="submit" className="btn" disabled={busy || !code.trim()}>
+          {busy ? 'Checking…' : 'Link account'}
+        </button>
+      </div>
+
+      {message && (
+        <p className="sans" style={{ color: '#7fd0a4', fontSize: '0.86rem', margin: '10px 0 0' }}>{message}</p>
+      )}
+      {error && (
+        <p className="sans" style={{ color: '#e05a5a', fontSize: '0.86rem', margin: '10px 0 0' }}>{error}</p>
+      )}
+    </form>
+  )
+}
+
+/** One linked account, and the control that releases it. */
+function LinkRow({ link, onRemoved }) {
+  const [busy, setBusy] = useState(false)
+  const [error, setError] = useState('')
+
+  async function remove() {
+    setBusy(true)
+    setError('')
+    try {
+      await api.playerLinks.remove(link.steamId)
+      await onRemoved()
+    } catch (err) {
+      setError(err.message || 'Could not unlink that account.')
+      setBusy(false)
+    }
+  }
+
+  return (
+    <li className="panel" style={{ padding: '14px 16px', display: 'flex', alignItems: 'center', gap: 14 }}>
+      <div style={{ minWidth: 0, flex: 1 }}>
+        <div className="display" style={{ fontSize: '1rem', color: 'var(--head)' }}>
+          {link.name || shortId(link.steamId)}
+        </div>
+        <div className="sans dim" style={{ fontSize: '0.76rem', marginTop: 2 }}>
+          {link.steamId} · linked {ago(link.linkedAt)}
+          {link.serverId ? ` on ${link.serverId}` : ''}
+        </div>
+        {error && (
+          <p className="sans" style={{ color: '#e05a5a', fontSize: '0.8rem', margin: '6px 0 0' }}>{error}</p>
+        )}
+      </div>
+      <button type="button" className="btn ghost" onClick={remove} disabled={busy} style={{ flex: 'none' }}>
+        {busy ? 'Unlinking…' : 'Unlink'}
+      </button>
+    </li>
+  )
+}
+
+export default function Account() {
+  // `useAsync` rather than this module's `usePolled`: nothing here changes unless
+  // the person looking at it changes it, and a page that re-asked every twenty
+  // seconds would be asking a question nobody is waiting on.
+  //
+  // **Core's `useAsync` has no `refresh`** — it re-runs when its deps change and
+  // that is the whole of its interface — so a counter in the deps is how a page
+  // re-reads after its own write. It blanks while it re-reads, which is right
+  // here and is exactly what made it wrong for a poll (see `hooks/usePolled.js`).
+  const [reloads, setReloads] = useState(0)
+  const { data, loading, error } = useAsync(() => api.playerLinks.list(), [reloads])
+  const links = data ? data.links : []
+
+  const reload = useCallback(() => setReloads((n) => n + 1), [])
+
+  return (
+    <div>
+      <div className="field-label" style={{ marginBottom: 12 }}>Steam accounts</div>
+
+      <p className="sans dim" style={{ margin: 0, fontSize: '0.86rem', maxWidth: '60ch' }}>
+        Linking tells this site which Steam account is yours, so your play on our servers appears
+        under your name here — and so rewards and permissions the site hands out can reach you in
+        game.
+      </p>
+
+      <ol className="sans dim" style={{ fontSize: '0.86rem', marginTop: 14, paddingLeft: 20, maxWidth: '60ch' }}>
+        <li>Join any of our Rust servers and type <code>/link</code> in chat.</li>
+        <li>The server replies with a six-character code, only you can see it, and it lasts five minutes.</li>
+        <li>Type it below. It works once.</li>
+      </ol>
+
+      <LinkForm onLinked={reload} />
+
+      {loading && <Loading />}
+      {error && <ErrorState error={error} />}
+
+      {data && links.length > 0 && (
+        <ul style={{ listStyle: 'none', margin: '22px 0 0', padding: 0, display: 'flex', flexDirection: 'column', gap: 10 }}>
+          {links.map((link) => (
+            <LinkRow key={link.steamId} link={link} onRemoved={reload} />
+          ))}
+        </ul>
+      )}
+
+      {data && links.length > 0 && (
+        <p className="sans dim" style={{ fontSize: '0.76rem', marginTop: 14, maxWidth: '60ch' }}>
+          A link covers every server this community runs — a Steam account is one person wherever
+          they play, while stats are kept per server and per wipe. You can also type
+          {' '}<code>/unlink</code> in game to release one.
+        </p>
+      )}
+
+      {data && links.length === 0 && (
+        <p className="sans dim" style={{ fontSize: '0.8rem', marginTop: 18 }}>
+          No Steam account is linked to this profile yet.
+        </p>
+      )}
+    </div>
+  )
+}