feat: split options settings into compact swap and transfer cards with aligned columns

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/options/templates/options_settings_swap.html

@@ -0,0 +1,12 @@
+<div class="options-settings-section">
+    <p class="options-settings-hint">主账户资金账户：USDT ↔ USDC，走 USDC-USDT 现货市价单。</p>
+    <div class="form-row options-settings-row">
+        <select id="opt-set-swap-dir">
+            <option value="usdt_to_usdc" selected>USDT → USDC</option>
+            <option value="usdc_to_usdt">USDC → USDT</option>
+        </select>
+        <input type="number" id="opt-set-swap-amount" min="0.01" step="0.01" placeholder="数量">
+        <button type="button" class="btn-primary btn-sm" id="opt-set-swap-btn">市价兑换</button>
+    </div>
+    <div id="opt-set-swap-msg" class="options-settings-msg muted"></div>
+</div>