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/components/category-combobox.tsx

@@ -1,4 +1,4 @@
-import { useState } from "react";
+import { useState, useEffect } from "react";
 import { Check, ChevronsUpDown } from "lucide-react";
 import { cn } from "@/lib/utils";
 import { Button } from "@/components/ui/button";
@@ -26,6 +26,11 @@ interface CategoryComboboxProps {
 export function CategoryCombobox({ value, onChange, placeholder = "Select or type a category..." }: CategoryComboboxProps) {
   const [open, setOpen] = useState(false);
   const [inputValue, setInputValue] = useState(value);
+
+  useEffect(() => {
+    setInputValue(value);
+  }, [value]);
+
   const categories = useListCategories({
     query: {
       queryKey: getListCategoriesQueryKey(),