P1-P3 admin cleanup: rank guard, SSRF guard, count caching, dead code removal, pagination rewrite

- P1: new src/lib/admin/rank-guard.ts with tryGuardRank/guardRank + RankGuardTarget/Result; extracted from users.ts; applied to admin-bans (create/lift + rank redirect) and admin-badges (caps + rank guard + error surfacing); import-url-safety.ts SSRF guard wired into clone save+icon fetch; logAudit await in help-tickets; antiddos mutations SETTINGS_EDIT; markAllAlertsRead NOTIFICATIONS_EDIT; rankError/saveError in all 25 message files; tests rew/new for bans/badges/rank-guard/import-url-safety

- P2: ticket-inbox merged pagination reworked to single UNION ALL SQL with LIMIT/OFFSET (avoids O(offset) materialization); getCachedAdminCount with cacheFiltered option applied to devops/errors/photos/items/guilds/help-tickets/moderation pages; admin-theme catches→?error=1+banner+25 locales; logger in silent catches (rare-values/writeable-boxes); catalog-items-loader CAST→plain equality; count caching helper extended with opt-in cacheFiltered

- P3: removed dead modules is-staff/notice/recent-furni-resync/log-filters plus load-user-sanctions/user-sanction-timeline; removed orphaned CATALOG_PAGE_COLUMNS re-export; removed getFurniIconUrl from studio-furni-icons

Build: lint 0, typecheck 0, 3480 tests pass, i18n:check exit 0, colors exit 0. Circular chunk warning (9452/10535/66463) is webpack code-splitting artifact; build succeeds.

src/messages/en.json

@@ -1982,7 +1982,8 @@
 				"reasonPlaceholder": "Reason for the ban",
 				"ban": "Ban user",
 				"colUserId": "User ID",
-				"lift": "Lift ban"
+				"lift": "Lift ban",
+				"rankError": "You cannot act on a user with an equal or higher rank."
 			},
 			"ip": {
 				"title": "IP Management",
@@ -4620,7 +4621,8 @@
 					"border2pxsolidred": "border: 2px solid red;",
 					"CustomHTML": "Custom HTML",
 					"AddcustomHTMLthatinjectsintothepageforthisscopeUseforcustombannersscriptsorcontentblocks": "Add custom HTML that injects into the page for this scope. Use for custom banners, scripts, or content blocks."
-				}
+				},
+				"saveError": "The theme change could not be saved."
 			},
 			"media": {
 				"title": "Media Library",