fix: security hardening, validation, cache and analytics fixes

Backend security:
- Admin-gate /admin/redundancy (GET+POST) with zod validation and tool existence checks
- Restrict CORS to same-origin (plus CORS_ORIGIN allowlist) and SameSite=Lax cookie
- Validate returnTo to prevent open redirect in the OIDC flow
- Validate/coerce relations body, reject self-relations and non-admin 'recommended'
- Add central JSON error middleware (no more Express HTML 500s)
- Fail fast at startup when SESSION_SECRET/VOTER_SECRET missing in production

Backend correctness:
- Stop leaking voterToken in the create-rating response
- Allow clearing websiteUrl/iconUrl (nullable in UpdateToolBody, frontend sends null)
- Regenerate session after login/callback (session fixation) and add OIDC state check
- Block self-demotion and last-admin demotion in user PATCH
- Set created_by to NULL on user delete (FK-safe)
- Validate cost create/update bodies with zod
- Unique index (tool_id, voter_token) + 409 on race duplicate ratings
- Clamp audit limit, escape ilike wildcards in search, O(N) analytics queries

Frontend:
- tools-browse reads and syncs URL query params (fixes home 'View all' links)
- Invalidate analytics/top-tools/categories/features caches after mutations
- Sync category combobox input when the value changes externally
- Hide Write a Review for anonymous users, drop unreachable rating guard

artifacts/toolrate/src/pages/tools-browse.tsx

@@ -1,4 +1,4 @@
-import { useState } from "react";
+import { useState, useEffect } from "react";
 import { 
   useListTools, 
   useListCategories,
@@ -11,13 +11,35 @@ import { Button } from "@/components/ui/button";
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select";
 import { Skeleton } from "@/components/ui/skeleton";
 import { Search, Wrench, SlidersHorizontal, X } from "lucide-react";
-import { Link } from "wouter";
+import { Link, useLocation, useSearch } from "wouter";
+
+const SORT_VALUES = new Set<string>([ListToolsSort.newest, ListToolsSort.top_rated, ListToolsSort.most_reviewed]);
 
 export default function ToolsBrowse() {
-  const [search, setSearch] = useState("");
-  const [searchInput, setSearchInput] = useState("");
-  const [category, setCategory] = useState<string>("all");
-  const [sort, setSort] = useState<ListToolsSort>(ListToolsSort.newest);
+  const [, navigate] = useLocation();
+  const urlSearch = useSearch();
+
+  const initialParams = new URLSearchParams(urlSearch);
+  const initialSearch = initialParams.get("search") ?? "";
+  const initialCategory = initialParams.get("category") ?? "all";
+  const initialSortParam = initialParams.get("sort") ?? "";
+  const initialSort = SORT_VALUES.has(initialSortParam)
+    ? (initialSortParam as ListToolsSort)
+    : ListToolsSort.newest;
+
+  const [search, setSearch] = useState(initialSearch);
+  const [searchInput, setSearchInput] = useState(initialSearch);
+  const [category, setCategory] = useState<string>(initialCategory);
+  const [sort, setSort] = useState<ListToolsSort>(initialSort);
+
+  useEffect(() => {
+    const p = new URLSearchParams();
+    if (search) p.set("search", search);
+    if (category && category !== "all") p.set("category", category);
+    if (sort && sort !== ListToolsSort.newest) p.set("sort", sort);
+    const qs = p.toString();
+    navigate(qs ? `/tools?${qs}` : "/tools", { replace: true });
+  }, [search, category, sort]);
 
   const { data: categories, isLoading: loadingCategories } = useListCategories();