feat: Implement Gogh Theme Engine with options page, theme parsing, and semantic theme derivation

We're cooked. <skull emoji>

- Added options page for YAML palette editing, live color preview, and diagnostics.
- Implemented theme engine to parse Gogh YAML palettes and derive semantic themes.
- Configured TypeScript and Vite for building the extension.
- Created new tab and popup HTML pages with corresponding scripts and styles.
- Established storage management for user configurations in Chrome storage.
- Added icons for the extension and updated manifest for MV3 compatibility.

popup/styles/_page.scss

@@ -0,0 +1,10 @@
+@import "./variables";
+
+body {
+    background-color: $light-gray;
+    color: $dark-gray;
+    font: {
+        family: $font-family;
+        size: 16px;
+    }
+}

popup/styles/_variables.scss

@@ -0,0 +1,3 @@
+$dark-gray: #830000;
+$light-gray: #fdffd0;
+$font-family: -apple-system, BlinkMacSystemFont,'Segoe UI',Roboto,Oxygen,Ubuntu,'Fira Sans','Droid Sans','Helvetica Neue',sans-serif;

popup/styles/popup.scss

@@ -0,0 +1,2 @@
+@import "./variables";
+@import "./page";