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/AdminLayout.jsx

@@ -113,6 +113,14 @@ const TITLES = {
   '/admin/account': 'Account Security',
 }
 
+// Fallback page title for dynamic sub-routes not in the exact-match TITLES map.
+function sectionTitle(pathname) {
+  if (pathname.startsWith('/admin/moderation')) return 'Moderation'
+  if (pathname.startsWith('/admin/characters')) return 'My Characters'
+  if (pathname.startsWith('/admin/users/')) return 'User'
+  return 'Admin'
+}
+
 const navBtnBase = {
   textAlign: 'left',
   borderRadius: 8,
@@ -131,15 +139,7 @@ export default function AdminLayout() {
   const { mode, siteTitle } = useSite()
   const navigate = useNavigate()
   const location = useLocation()
-  const title =
-    TITLES[location.pathname] ||
-    (location.pathname.startsWith('/admin/moderation')
-      ? 'Moderation'
-      : location.pathname.startsWith('/admin/characters')
-        ? 'My Characters'
-        : location.pathname.startsWith('/admin/users/')
-          ? 'User'
-          : 'Admin')
+  const title = TITLES[location.pathname] || sectionTitle(location.pathname)
   // The hero canvas editor needs room — let it use the full content width.
   const wide = location.pathname === '/admin/hero'
   const modeDot = mode === 'live' ? 'var(--mode-live)' : 'var(--mode-maint)'
@@ -236,7 +236,7 @@ export default function AdminLayout() {
         </div>
 
         <nav style={{ flex: 1, padding: '14px 12px', display: 'flex', flexDirection: 'column', gap: 4, overflowY: 'auto' }}>
-          {navGroups.map((group, gi) => {
+          {navGroups.map((group) => {
             const links = group.items.map((n) => (
               <NavLink
                 key={n.to}
@@ -258,7 +258,7 @@ export default function AdminLayout() {
             // Untitled groups (Dashboard, Account) render their links directly.
             if (!group.title) {
               return (
-                <div key={`g${gi}`} style={{ display: 'flex', flexDirection: 'column', gap: 4 }}>
+                <div key={group.items[0]?.to || 'group'} style={{ display: 'flex', flexDirection: 'column', gap: 4 }}>
                   {links}
                 </div>
               )