feat: redesign wallet login and favorites, fix desktop/mobile bugs

- Remove forced BNB chain switch on injected login (signature is chain-agnostic)
- Refine isMobileDevice so touch Macs stay on desktop flow
- Wire RainbowKit/WalletConnect as a real MetaMask/imToken QR fallback,
  gated on a valid VITE_WALLETCONNECT_PROJECT_ID
- Rebuild login modal: single desktop primary action, collapsible other
  methods, mobile open-app fallback feedback, brand icons
- Add My Favorites entry points (header, mobile menu, wallet dropdown)
- Favorites page: error retry, mobile filter drawer
- Auto sign-out and re-login prompt on favorites 401
- Full native translations for all wallet strings across 7 locales

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

src/wallet/injected.ts

@@ -2,8 +2,6 @@ import { requestWalletNonce, verifyWalletSignature } from "./api";
 
 export type WalletKind = "tokenPocket" | "metaMask" | "imToken";
 
-const bnbChainIdHex = "0x38";
-
 export type EthereumProvider = {
   isMetaMask?: boolean;
   isTokenPocket?: boolean;
@@ -36,30 +34,6 @@ export function getInjectedWallet(kind?: WalletKind): EthereumProvider | null {
   return match ?? null;
 }
 
-async function ensureBnbChain(ethereum: EthereumProvider): Promise<void> {
-  try {
-    await ethereum.request({
-      method: "wallet_switchEthereumChain",
-      params: [{ chainId: bnbChainIdHex }],
-    });
-  } catch (error) {
-    const code = (error as { code?: number | string }).code;
-    if (code !== 4902 && code !== "4902") throw error;
-    await ethereum.request({
-      method: "wallet_addEthereumChain",
-      params: [
-        {
-          blockExplorerUrls: ["https://bscscan.com"],
-          chainId: bnbChainIdHex,
-          chainName: "BNB Smart Chain",
-          nativeCurrency: { decimals: 18, name: "BNB", symbol: "BNB" },
-          rpcUrls: ["https://bsc-dataseed.binance.org"],
-        },
-      ],
-    });
-  }
-}
-
 export async function signInWithInjectedWallet(kind?: WalletKind): Promise<{
   token: string;
   wallet: string;
@@ -67,8 +41,9 @@ export async function signInWithInjectedWallet(kind?: WalletKind): Promise<{
   const ethereum = getInjectedWallet(kind);
   if (!ethereum) throw new Error("No injected wallet found");
 
-  await ensureBnbChain(ethereum);
-
+  // Login is signature-only (EIP-191 personal_sign). The backend verifies the
+  // recovered address and never inspects chainId, so we deliberately do NOT
+  // switch or add any chain — that only adds a failure-prone wallet popup.
   const accounts = await ethereum.request<string[]>({
     method: "eth_requestAccounts",
   });