feat: add SDK playground, unit tests, WalletConnect experiment, and sender dashboard

frontend/app/sandbox/playground/page.tsx

@@ -0,0 +1,132 @@
+"use client";
+
+import { useState } from "react";
+import { BridgeletClient } from "@/lib/create-bridgelet-client";
+import type { BridgeletClientOptions } from "@/lib/create-bridgelet-client";
+
+type Endpoint = "getClaimDetails" | "createPaymentIntent" | "redeemClaim";
+
+const ENDPOINT_LABELS: Record<Endpoint, string> = {
+  getClaimDetails: "GET /claim/:token",
+  createPaymentIntent: "POST /send",
+  redeemClaim: "POST /claim/:token/redeem",
+};
+
+const INITIAL_PARAMS: Record<Endpoint, Record<string, string>> = {
+  getClaimDetails: { token: "demo_token_here" },
+  createPaymentIntent: { senderPublicKey: "G...", amountStroops: "10000000", assetCode: "USDC" },
+  redeemClaim: { token: "demo_token_here", recipientPublicKey: "G..." },
+};
+
+export default function PlaygroundPage() {
+  const [selected, setSelected] = useState<Endpoint>("getClaimDetails");
+  const [params, setParams] = useState<Record<string, string>>(INITIAL_PARAMS.getClaimDetails);
+  const [response, setResponse] = useState<string>("");
+  const [error, setError] = useState<string>("");
+  const [loading, setLoading] = useState(false);
+
+  const client = new BridgeletClient({
+    baseUrl: process.env.NEXT_PUBLIC_API_BASE_URL,
+    apiKey: process.env.NEXT_PUBLIC_API_KEY,
+  } as BridgeletClientOptions);
+
+  const handleEndpointChange = (endpoint: Endpoint) => {
+    setSelected(endpoint);
+    setParams(INITIAL_PARAMS[endpoint]);
+    setResponse("");
+    setError("");
+  };
+
+  const handleParamChange = (key: string, value: string) => {
+    setParams((prev) => ({ ...prev, [key]: value }));
+  };
+
+  const execute = async () => {
+    setLoading(true);
+    setResponse("");
+    setError("");
+    try {
+      let result: unknown;
+      switch (selected) {
+        case "getClaimDetails":
+          result = await client.getClaimDetails(params.token);
+          break;
+        case "createPaymentIntent":
+          result = await client.createPaymentIntent({
+            senderPublicKey: params.senderPublicKey,
+            amountStroops: params.amountStroops,
+            assetCode: params.assetCode,
+          });
+          break;
+        case "redeemClaim":
+          result = await client.redeemClaim(params.token, {
+            recipientPublicKey: params.recipientPublicKey,
+          });
+          break;
+      }
+      setResponse(JSON.stringify(result, null, 2));
+    } catch (err) {
+      setError(JSON.stringify(err, null, 2));
+    } finally {
+      setLoading(false);
+    }
+  };
+
+  return (
+    <main className="p-8 max-w-2xl mx-auto space-y-6">
+      <h1 className="text-xl font-bold">Bridgelet SDK Playground</h1>
+      <p className="text-sm text-slate-500">Test SDK endpoints and inspect raw responses.</p>
+
+      <div className="flex gap-2 flex-wrap">
+        {(Object.keys(ENDPOINT_LABELS) as Endpoint[]).map((ep) => (
+          <button
+            key={ep}
+            onClick={() => handleEndpointChange(ep)}
+            className={`rounded px-3 py-1.5 text-sm font-medium transition-colors ${
+              selected === ep
+                ? "bg-slate-900 text-white"
+                : "bg-slate-100 text-slate-700 hover:bg-slate-200"
+            }`}
+          >
+            {ENDPOINT_LABELS[ep]}
+          </button>
+        ))}
+      </div>
+
+      <div className="rounded-lg border p-4 space-y-3 bg-slate-50">
+        <h2 className="text-sm font-semibold text-slate-700">Parameters</h2>
+        {Object.entries(params).map(([key, val]) => (
+          <div key={key} className="flex items-center gap-2">
+            <label className="text-xs font-mono text-slate-500 w-40">{key}</label>
+            <input
+              value={val}
+              onChange={(e) => handleParamChange(key, e.target.value)}
+              className="flex-1 rounded border px-2 py-1 text-sm font-mono"
+            />
+          </div>
+        ))}
+        <button
+          onClick={execute}
+          disabled={loading}
+          className="rounded bg-slate-900 px-4 py-2 text-sm text-white hover:bg-slate-700 disabled:opacity-50"
+        >
+          {loading ? "Executing..." : "Execute"}
+        </button>
+      </div>
+
+      {response && (
+        <div className="rounded-lg border border-green-200 p-4 space-y-2 bg-green-50">
+          <h2 className="text-sm font-semibold text-green-700">Response</h2>
+          <pre className="text-xs font-mono whitespace-pre-wrap bg-white rounded p-3 border">{response}</pre>
+        </div>
+      )}
+
+      {error && (
+        <div className="rounded-lg border border-red-200 p-4 space-y-2 bg-red-50">
+          <h2 className="text-sm font-semibold text-red-700">Error</h2>
+          <pre className="text-xs font-mono whitespace-pre-wrap bg-white rounded p-3 border">{error}</pre>
+        </div>
+      )}
+    </main>
+  );
+}