fix: keep desktop browser-wallet on direct injected; add login diagnostics

Revert desktop primary back to the direct injected sign (no WalletConnect relay,
which could spin forever) — reliable for a BNB-chain extension. Add console
diagnostics ([wallet-login] ...) and provider enumeration so a stuck/no-popup
flow can be pinpointed. WalletConnect stays as the explicit mobile MetaMask/
imToken option.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/wallet/WalletLoginModal.tsx

@@ -146,18 +146,6 @@ export function WalletLoginModal() {
       .finally(() => setState("idle"));
   };
 
-  // Desktop: open the RainbowKit modal — it discovers every installed wallet
-  // via EIP-6963 (robust when several extensions fight over window.ethereum)
-  // and also offers a WalletConnect QR. Fall back to the raw injected flow only
-  // when WalletConnect has no project id configured.
-  const connectBrowserWallet = () => {
-    if (wc.available) {
-      wc.start();
-      return;
-    }
-    void signInjected();
-  };
-
   const openApp = (kind: WalletKind) => {
     setError("");
     setOpeningWallet(kind);
@@ -213,29 +201,20 @@ export function WalletLoginModal() {
         </div>
 
         <div className="mt-5 grid gap-3">
-          {/* Browser wallet: in a wallet's in-app browser we sign directly with
-              the injected provider; on desktop we open the RainbowKit picker so
-              the user can choose among installed extensions reliably. */}
-          {mobileDevice && hasInjected ? (
+          {/* Browser wallet: sign directly with the injected provider — the
+              reliable path for a BNB-chain extension (desktop) or a wallet's
+              in-app browser. No WalletConnect relay involved. */}
+          {!mobileDevice || hasInjected ? (
             <button
               type="button"
               onClick={() => void signInjected()}
               disabled={busy}
               className="flex items-center justify-center gap-2 rounded-2xl bg-ark-gold px-4 py-4 text-base font-bold text-black transition hover:bg-ark-gold2 disabled:cursor-wait disabled:opacity-70"
             >
-              {state === "signing" ? t("walletSigning") : t("walletUseCurrent")}
-            </button>
-          ) : !mobileDevice ? (
-            <button
-              type="button"
-              onClick={connectBrowserWallet}
-              disabled={busy || wc.state !== "idle"}
-              className="flex items-center justify-center gap-2 rounded-2xl bg-ark-gold px-4 py-4 text-base font-bold text-black transition hover:bg-ark-gold2 disabled:cursor-wait disabled:opacity-70"
-            >
-              {wc.state === "connecting"
-                ? t("walletConnecting")
-                : wc.state === "signing" || state === "signing"
-                  ? t("walletSigning")
+              {state === "signing"
+                ? t("walletSigning")
+                : mobileDevice
+                  ? t("walletUseCurrent")
                   : t("walletInjected")}
             </button>
           ) : null}