Error Feedback Service + friendly error handling across all pages

- Error Feedback Service: POST /api/feedback saves to JSONL, GET with admin token
- ErrorFeedback component: warm amber tones, friendly messages, 'Report Issue' button
- Replaced ALL red-themed error displays across 15+ pages with ErrorFeedback
- Kind classification: network, auth, location, upgrade, default messages
- QA test suite v2: 8-layer testing (system, API, render, scenario, edge, mobile, perf, security)
- Browser-based visual QA with Playwright (Layer 9)

src/app/wallet/page.tsx

@@ -17,6 +17,7 @@ import {
   Sparkles,
   Info,
 } from "lucide-react";
+import ErrorFeedback from "@/components/ErrorFeedback";
 
 interface CashoutEntry {
   id: string;
@@ -224,22 +225,15 @@ export default function WalletPage() {
         </div>
 
         {/* Messages */}
-        {cashoutMessage && (
-          <div
-            className={`flex items-center gap-2 p-3 rounded-xl text-sm ${
-              cashoutMessage.type === "success"
-                ? "bg-emerald-900/20 border border-emerald-800/40 text-emerald-400"
-                : "bg-red-900/20 border border-red-800/40 text-red-400"
-            }`}
-          >
-            {cashoutMessage.type === "success" ? (
-              <Check size={16} />
-            ) : (
-              <X size={16} />
-            )}
+        {cashoutMessage && cashoutMessage.type === "success" && (
+          <div className="flex items-center gap-2 p-3 rounded-xl text-sm bg-emerald-900/20 border border-emerald-800/40 text-emerald-400">
+            <Check size={16} />
             {cashoutMessage.text}
           </div>
         )}
+        {cashoutMessage && cashoutMessage.type === "error" && (
+          <ErrorFeedback error={cashoutMessage.text} kind="default" onRetry={() => setCashoutMessage(null)} context="wallet" />
+        )}
 
         {/* Top-Up Section */}
         <div>