feat(recharge): add points recharge agreement flow

- add new API request for fetching points top up agreement content
- update recharge footer with agreement checkbox and protocol link
- add agreement popup modal to display full agreement text
- add payment pre-validation to enforce agreement acceptance before payment
- handle loading and error states for agreement retrieval
- adjust recharge footer layout to accommodate new UI elements

src/pages-aigc/recharge/components/RechargeFooter/styles/index.scss

@@ -1,10 +1,9 @@
 .recharge-footer {
   position: sticky;
   bottom: 12px;
-  display: grid;
-  grid-template-columns: 1fr 142px;
-  align-items: center;
-  gap: 10px;
+  display: flex;
+  flex-direction: column;
+  gap: 12px;
   margin-top: 16px;
   padding: 12px;
   border-radius: 20px;
@@ -13,6 +12,38 @@
   box-sizing: border-box;
 }
 
+.recharge-agreement {
+  display: flex;
+  align-items: center;
+  box-sizing: border-box;
+}
+
+.recharge-agreement.is-disabled {
+  opacity: 0.56;
+}
+
+.recharge-agreement-text,
+.recharge-agreement-link {
+  font-size: 14px;
+  line-height: 24px;
+}
+
+.recharge-agreement-text {
+  color: #667386;
+}
+
+.recharge-agreement-link {
+  color: $theme-color-600;
+  font-weight: 700;
+}
+
+.recharge-payment-row {
+  display: grid;
+  grid-template-columns: minmax(0, 1fr) 142px;
+  align-items: center;
+  gap: 10px;
+}
+
 .recharge-gain {
   min-width: 0;
   overflow: hidden;