feat: add OKX options module with dual API, USDT/USDC convert, and docs

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

lib/common/static/instance_theme.css

@@ -2326,3 +2326,68 @@ html[data-theme="light"] .settings-export-link {
   color: #1d4f8c;
 }
 
+/* OKX 期权页 */
+.options-funds-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
+  gap: 12px;
+  margin: 12px 0 16px;
+}
+.options-funds-col {
+  background: rgba(255, 255, 255, 0.03);
+  border: 1px solid rgba(255, 255, 255, 0.06);
+  border-radius: 8px;
+  padding: 12px;
+}
+.options-fund-row {
+  display: flex;
+  justify-content: space-between;
+  gap: 8px;
+  margin: 6px 0;
+  font-size: 0.9rem;
+}
+.options-section {
+  margin: 16px 0;
+}
+.options-section.card-nested {
+  padding: 12px;
+  border-radius: 8px;
+  background: rgba(0, 0, 0, 0.15);
+}
+.options-strike-table-wrap {
+  overflow-x: auto;
+  margin-top: 8px;
+}
+.options-strike-table {
+  width: 100%;
+  border-collapse: collapse;
+  font-size: 0.85rem;
+}
+.options-strike-table th,
+.options-strike-table td {
+  padding: 8px 6px;
+  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
+  text-align: left;
+}
+.options-chain-toolbar .btn-secondary.active,
+.opt-uly-btn.active,
+.opt-type-btn.active {
+  border-color: #4a7cff;
+  color: #9ec0ff;
+}
+.options-order-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
+  gap: 10px;
+  margin: 10px 0;
+}
+.options-order-grid .k {
+  display: block;
+  font-size: 0.78rem;
+  color: #8892b0;
+}
+.options-hint {
+  font-size: 0.85rem;
+  margin-bottom: 8px;
+}
+