feat: init fitness-coach (backend + miniprogram)

- backend: NestJS service with exercise/plan data
- miniprogram: WeChat mini program client
- exclude node_modules, dist, runtime data-store, local env

miniprogram/components/chip/index.wxss

@@ -0,0 +1,18 @@
+.chip {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  padding: 12rpx 26rpx;
+  border-radius: 999rpx;
+  background: var(--surface-2);
+  color: var(--text-2);
+  font-size: 24rpx;
+  border: 1rpx solid var(--line);
+  transition: all .15s ease;
+  white-space: nowrap;
+}
+.chip--active {
+  background: var(--gold-soft);
+  color: var(--gold-2);
+  border-color: var(--gold-line);
+}