feat(aigc): add video save support and improve consent flow

- add support for saving both image and video AIGC generation results
- refactor ResultActions component to accept mediaType prop and use dynamic save button text
- remove AIGC consent dialog from ChatQuickAccess and implement it on AIGC home page
- add WeChat mini-program privacy authorization check before saving media
- create reusable AigcConsentDialog component with proper styling

src/pages-aigc/home/components/AigcConsentDialog/styles/index.scss

@@ -0,0 +1,75 @@
+.aigc-consent-overlay {
+  width: 100vw;
+  padding: 0 28px;
+  box-sizing: border-box;
+}
+
+.aigc-consent-dialog {
+  width: 100%;
+  padding: 34px 28px 26px;
+  border-radius: 24px;
+  background: #ffffff;
+  box-shadow: 0 18px 48px rgba(0, 0, 0, 0.26);
+  box-sizing: border-box;
+}
+
+.aigc-consent-title {
+  display: block;
+  margin-bottom: 24px;
+  color: #111827;
+  font-size: 19px;
+  line-height: 26px;
+  font-weight: 900;
+  text-align: center;
+}
+
+.aigc-consent-content {
+  color: #606776;
+  font-size: 14px;
+  line-height: 25px;
+  font-weight: 700;
+  text-align: justify;
+}
+
+.aigc-consent-rule {
+  color: #18bd78;
+  font-weight: 900;
+}
+
+.aigc-consent-actions {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: 18px;
+  margin-top: 28px;
+}
+
+.aigc-consent-button {
+  width: 100%;
+  height: 54px;
+  margin: 0;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  padding: 0;
+  border-radius: 999px;
+  font-size: 16px;
+  line-height: 22px;
+  font-weight: 900;
+  box-sizing: border-box;
+}
+
+.aigc-consent-button::after {
+  border: 0;
+}
+
+.aigc-consent-cancel {
+  border: 1px solid #e2e6ea;
+  background: #ffffff;
+  color: #172033;
+}
+
+.aigc-consent-agree {
+  border: 1px solid #061c31;
+  background: #061c31;
+  color: #ffffff;
+}