chore(quality): resolve SonarQube code smells across website

Clears the 124 CODE_SMELL findings from the SonarQube scan (server, client,
and bot). All changes are behaviour-preserving refactors — no route, protocol,
schema, or config changes — verified against the full server (381) and client
(43) test suites plus a clean client build.

By rule:
- S3776 (20, cognitive complexity): extract helpers/handlers so each function
  drops under the threshold — shard model upsert builders, page/wiki update,
  block validation, notification stream mapping (dispatch table), SSO mobile
  login, shard ingest deps, uo-link socket backfill/connect, the bot slash-
  command dispatchers + discord manager, and the Shard/UserDetail/HeroEditor/
  CharacterStats React components.
- S4624 (34, nested template literals): pull inner templates into locals /
  a withQs() helper; rewrite shardEvents.describe() as a formatter table.
- S3358 (35, nested ternaries): lift to if/else vars, lookup maps, small
  components, or guarded JSX expressions.
- S6479 (12, array-index React keys): key by stable content instead of index
  (two in-editor lists left as-is; index matches their by-index edit model).
- S6353 (6): [0-9]/[^0-9] -> \d/\D.  S125 (5): reword state-shape comments that
  parsed as code.  S3800/S3782 (botScore): JSDoc-type PATH_WEIGHTS tuples.
- S6481 (2): memoize Auth/Site context values (and SiteContext brand).
- S4144: dedupe HeroEditor upload handler into useImageUpload().
- S1126 (2), S6035, S5869 (redundant A-Z under /i), S5843 (town-name regex ->
  prefix list): assorted one-liners.

Co-Authored-By: Claude <noreply@anthropic.com>

client/src/routes/player/AcceptInvite.jsx

@@ -14,7 +14,7 @@ export default function AcceptInvite() {
   const navigate = useNavigate()
   const { refresh } = useAuth()
 
-  const [invite, setInvite] = useState(null) // { email, role }
+  const [invite, setInvite] = useState(null) // fields email and role
   const [loadErr, setLoadErr] = useState('')
   const [signupOk, setSignupOk] = useState(false)
 

client/src/routes/player/PlayerAccount.jsx

@@ -75,6 +75,9 @@ function ChangePassword({ account }) {
     }
   }
 
+  let pwLabel = hasPassword ? 'Change password' : 'Set password'
+  if (busy) pwLabel = 'Saving…'
+
   return (
     <Section title={hasPassword ? 'Password' : 'Set a password'}>
       {!hasPassword && (
@@ -96,7 +99,7 @@ function ChangePassword({ account }) {
         </label>
         <div>
           <button type="submit" disabled={busy} className="btn btn-primary btn-sq">
-            {busy ? 'Saving…' : hasPassword ? 'Change password' : 'Set password'}
+            {pwLabel}
           </button>
         </div>
         <Note msg={msg} error={error} />

client/src/routes/player/PlayerLogin.jsx

@@ -125,6 +125,10 @@ export default function PlayerLogin() {
     }
   }
 
+  let submitLabel = 'Sign in'
+  if (busy) submitLabel = 'Signing in…'
+  else if (stage === 'totp') submitLabel = 'Verify'
+
   return (
     <PlayerShell
       subtitle="Player sign-in"
@@ -181,7 +185,7 @@ export default function PlayerLogin() {
         )}
 
         <button type="submit" disabled={busy} className="btn btn-primary" style={{ display: 'block', width: '100%', borderRadius: 8, padding: 12, textAlign: 'center' }}>
-          {busy ? 'Signing in…' : stage === 'totp' ? 'Verify' : 'Sign in'}
+          {submitLabel}
         </button>
 
         {stage === 'creds' && providers.length > 0 && (

client/src/routes/player/PlayerRegister.jsx

@@ -75,15 +75,17 @@ export default function PlayerRegister() {
         </p>
       }
     >
-      {avail === null ? (
+      {avail === null && (
         <div style={{ display: 'grid', placeItems: 'center', padding: 20 }}>
           <span className="spin" />
         </div>
-      ) : closed ? (
+      )}
+      {avail !== null && closed && (
         <p className="sans" style={{ margin: 0, color: 'var(--muted)', fontSize: '0.9rem', textAlign: 'center', lineHeight: 1.6 }}>
           Self-registration is currently closed. Please check back later.
         </p>
-      ) : (
+      )}
+      {avail !== null && !closed && (
         <>
           {avail.password && (
             <form onSubmit={onSubmit}>