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/admin/views/InvitesAdmin.jsx

@@ -43,7 +43,7 @@ function CreateInvite({ onCreated }) {
   const [sendEmail, setSendEmail] = useState(true)
   const [busy, setBusy] = useState(false)
   const [error, setError] = useState('')
-  const [result, setResult] = useState(null) // { emailed, acceptUrl, emailError }
+  const [result, setResult] = useState(null) // fields emailed, acceptUrl, emailError
 
   async function submit(e) {
     e.preventDefault()
@@ -62,6 +62,16 @@ function CreateInvite({ onCreated }) {
     }
   }
 
+  const submitLabel = sendEmail ? 'Create & email' : 'Create link'
+
+  let resultText
+  if (result?.emailed) {
+    resultText = 'Invitation emailed. You can also share this single-use link:'
+  } else {
+    const emailNote = result?.emailError ? ` (email not sent: ${result.emailError})` : ''
+    resultText = `Invite created${emailNote}. Share this single-use link:`
+  }
+
   return (
     <div className="panel" style={{ padding: 22, marginBottom: 22 }}>
       <div className="field-label" style={{ marginBottom: 10 }}>Invite someone</div>
@@ -77,7 +87,7 @@ function CreateInvite({ onCreated }) {
           </select>
         </label>
         <button type="submit" disabled={busy} className="btn btn-primary btn-sq">
-          {busy ? 'Creating…' : (sendEmail ? 'Create & email' : 'Create link')}
+          {busy ? 'Creating…' : submitLabel}
         </button>
       </form>
 
@@ -90,9 +100,7 @@ function CreateInvite({ onCreated }) {
       {result && (
         <div style={{ marginTop: 14 }}>
           <p className="sans" style={{ margin: '0 0 8px', fontSize: '0.84rem', color: result.emailed ? '#7fd0a4' : 'var(--muted)' }}>
-            {result.emailed
-              ? 'Invitation emailed. You can also share this single-use link:'
-              : `Invite created${result.emailError ? ` (email not sent: ${result.emailError})` : ''}. Share this single-use link:`}
+            {resultText}
           </p>
           <CopyLink url={result.acceptUrl} />
         </div>