feat: add theme management with light and dark modes

- Implemented a new composable `useTheme` for managing theme state.
- Added functions to read and write theme preference to local storage.
- Applied theme styles to the DOM based on user preference.
- Introduced a toggle function to switch between light and dark themes.

refactor: enhance copilot plugin functionality

- Improved request handling with sequence and document versioning.
- Refactored ghost text handling to improve clarity and efficiency.
- Updated markdown insertion logic to handle parsed content more robustly.
- Enhanced error handling and logging for better debugging.

style: update global styles for light and dark themes

- Defined CSS variables for light and dark themes to streamline styling.
- Improved overall styling consistency and responsiveness.
- Added transitions for smoother theme changes and interactions.

.build-check/assets/vendor-micromark-util-decode-string-fHsnqYdj.js

@@ -0,0 +1 @@
+import{d as t}from"./vendor-decode-named-character-reference-C3-224fz.js";import{d as o}from"./vendor-micromark-util-decode-numeric-character-reference-CNs1qBpV.js";const n=/\\([!-/:-@[-`{-~])|&(#(?:\d{1,7}|x[\da-f]{1,6})|[\da-z]{1,31});/gi;function u(r){return r.replace(n,f)}function f(r,c,e){if(c)return c;if(e.charCodeAt(0)===35){const d=e.charCodeAt(1),a=d===120||d===88;return o(e.slice(a?2:1),a?16:10)}return t(e)||r}export{u as d};