feat: Complete light mode implementation with semantic theme system (#450)

- Add comprehensive light/dark mode CSS variables with semantic naming
- Implement theme-aware scrollbars using CSS variables
- Add light mode backgrounds: --bg-base, --bg-elevated, --bg-surface, etc.
- Add theme-aware borders: --border-base, --border-panel, --border-subtle
- Add semantic text colors: --foreground-secondary, --foreground-subtle
- Convert oklch colors to hex for better compatibility
- Add theme awareness to CodeMirror editors
- Update dark mode colors for consistency (background, sidebar, card, muted, input)
- Add Tailwind color mappings for semantic classes

Co-authored-by: Luke Gustafson <88517757+LukeGus@users.noreply.github.com>

package-lock.json

@@ -39,6 +39,7 @@
         "@types/qrcode": "^1.5.5",
         "@types/speakeasy": "^2.0.10",
         "@uiw/codemirror-extensions-langs": "^4.24.1",
+        "@uiw/codemirror-theme-github": "^4.25.4",
         "@uiw/react-codemirror": "^4.24.1",
         "@xterm/addon-clipboard": "^0.1.0",
         "@xterm/addon-fit": "^0.10.0",
@@ -5794,6 +5795,37 @@
         "@codemirror/language-data": ">=6.0.0"
       }
     },
+    "node_modules/@uiw/codemirror-theme-github": {
+      "version": "4.25.4",
+      "resolved": "https://registry.npmjs.org/@uiw/codemirror-theme-github/-/codemirror-theme-github-4.25.4.tgz",
+      "integrity": "sha512-M5zRT2vIpNsuKN0Lz+DwLnmhHW8Eddp1M9zC0hm3V+bvffmaSn/pUDey1eqGIv5xNNmjhqvDAz0a90xLYCzvSw==",
+      "license": "MIT",
+      "dependencies": {
+        "@uiw/codemirror-themes": "4.25.4"
+      },
+      "funding": {
+        "url": "https://jaywcjlove.github.io/#/sponsor"
+      }
+    },
+    "node_modules/@uiw/codemirror-themes": {
+      "version": "4.25.4",
+      "resolved": "https://registry.npmjs.org/@uiw/codemirror-themes/-/codemirror-themes-4.25.4.tgz",
+      "integrity": "sha512-2SLktItgcZC4p0+PfFusEbAHwbuAWe3bOOntCevVgHtrWGtGZX3IPv2k8IKZMgOXtAHyGKpJvT9/nspPn/uCQg==",
+      "license": "MIT",
+      "dependencies": {
+        "@codemirror/language": "^6.0.0",
+        "@codemirror/state": "^6.0.0",
+        "@codemirror/view": "^6.0.0"
+      },
+      "funding": {
+        "url": "https://jaywcjlove.github.io/#/sponsor"
+      },
+      "peerDependencies": {
+        "@codemirror/language": ">=6.0.0",
+        "@codemirror/state": ">=6.0.0",
+        "@codemirror/view": ">=6.0.0"
+      }
+    },
     "node_modules/@uiw/react-codemirror": {
       "version": "4.25.2",
       "resolved": "https://registry.npmjs.org/@uiw/react-codemirror/-/react-codemirror-4.25.2.tgz",