feat: establish teaching feedback mini program

Connect student profiles, defaults, and feedback records to the Rust API. Configure the WeChat AppID, custom tab bar, and local development workflow for version 0.1.0.

pages/defaults/index.wxss

@@ -0,0 +1,106 @@
+.defaults-page {
+  padding-top: 38rpx;
+}
+
+.top-row {
+  display: flex;
+  align-items: flex-end;
+  justify-content: space-between;
+  gap: 18rpx;
+}
+
+.top-row .page-heading {
+  max-width: 480rpx;
+}
+
+.top-row .page-title {
+  font-size: 46rpx;
+}
+
+.reload-button {
+  flex: none;
+  min-width: 148rpx;
+  min-height: 70rpx;
+  font-size: 26rpx;
+}
+
+.defaults-card {
+  margin-top: 34rpx;
+  padding: 24rpx;
+}
+
+.defaults-grid {
+  display: flex;
+  gap: 16rpx;
+}
+
+.defaults-grid .select-field {
+  width: calc((100% - 16rpx) / 2);
+}
+
+.select-field,
+.duration-field {
+  padding: 24rpx;
+  border: 2rpx solid #d8e5f2;
+  border-radius: 14rpx;
+  background: #fbfdff;
+}
+
+.select-field {
+  min-height: 158rpx;
+}
+
+.duration-field {
+  margin-top: 16rpx;
+}
+
+.duration-input-row {
+  display: flex;
+  align-items: center;
+  gap: 12rpx;
+  margin-top: 20rpx;
+}
+
+.duration-input {
+  width: 150rpx;
+  height: 64rpx;
+  padding: 0 16rpx;
+  border: 2rpx solid #bed4e8;
+  border-radius: 12rpx;
+  background: #ffffff;
+  color: #17233a;
+  font-size: 38rpx;
+  font-weight: 800;
+  text-align: center;
+}
+
+.duration-unit {
+  color: #65758a;
+  font-size: 28rpx;
+}
+
+.duration-slider {
+  margin: 12rpx -12rpx 0;
+}
+
+.duration-bounds {
+  display: flex;
+  justify-content: space-between;
+  color: #8a97a6;
+  font-size: 23rpx;
+}
+
+.time-help {
+  margin-top: 18rpx;
+  padding: 20rpx;
+  border: 2rpx dashed #c6ddea;
+  border-radius: 12rpx;
+  color: #65758a;
+  font-size: 25rpx;
+  line-height: 1.5;
+}
+
+.save-defaults {
+  width: 420rpx;
+  margin: 26rpx auto 4rpx;
+}