feat: Enhance Obsidian Halo Plugin with comprehensive design system and component styles

- Updated styles.css to implement a three-layer design token architecture: Primitive, Semantic, and Component.
- Introduced new CSS variables for colors, spacing, typography, and shadows.
- Developed styles for buttons, cards, inputs, textareas, selects, badges, tables, modals, forms, color pickers, empty states, and loading spinners.
- Improved sync status view with responsive design and enhanced UI elements.
- Added skeleton loading animations for better user experience.

chore: Add configuration files for development environment

- Created .claude/settings.json to enable commit commands plugin.
- Added .vscode/c_cpp_properties.json for C/C++ IntelliSense configuration.
- Introduced .vscode/launch.json for debugging C/C++ applications with GDB.

.vscode/launch.json

@@ -0,0 +1,24 @@
+{
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "name": "C/C++ Runner: Debug Session",
+      "type": "cppdbg",
+      "request": "launch",
+      "args": [],
+      "stopAtEntry": false,
+      "externalConsole": true,
+      "cwd": "d:/Code/Obsidian/.obsidian/plugins/halo",
+      "program": "d:/Code/Obsidian/.obsidian/plugins/halo/build/Debug/outDebug",
+      "MIMode": "gdb",
+      "miDebuggerPath": "gdb",
+      "setupCommands": [
+        {
+          "description": "Enable pretty-printing for gdb",
+          "text": "-enable-pretty-printing",
+          "ignoreFailures": true
+        }
+      ]
+    }
+  ]
+}