refactor: restructure pinia stores, fix calendar, add utilities

- Restructure Pinia store organization from src/stores/ to src/store/ with modular stores
- Update main.ts to use locally created Pinia instance instead of imported pre-configured one
- Fix template syntax errors in Calendar component: correct missing class spacing and incorrect closing tags
- Remove unused calendar demo/example files and documentation
- Add new constant files, token management utilities, and client configuration constants
- Add custom hooks useGoHome and useGoLogin for navigation and login logic

src/hooks/useGoHome.ts

@@ -0,0 +1 @@
+export const goHome = () => uni.reLaunch({ url: "/pages/index/index" });