feat: Implement skill management functionality

- Added skill scope helpers and CRUD operations for skills in opencodeConfig.ts.
- Introduced API endpoints for skill management in main.tsx and index.js.
- Enhanced server-side logic to support skill discovery, creation, updating, and deletion.
- Implemented supporting file operations for skills, including reading, writing, and deleting files.
- Updated package.json to use the latest version of @opencode-ai/sdk.

packages/ui/src/constants/sidebar.ts

@@ -1,7 +1,7 @@
-import { RiBrainAi3Line, RiChatAi3Line, RiCommandLine, RiGitBranchLine, RiSettings3Line, RiStackLine } from '@remixicon/react';
+import { RiBrainAi3Line, RiChatAi3Line, RiCommandLine, RiGitBranchLine, RiSettings3Line, RiStackLine, RiBookLine } from '@remixicon/react';
 import type { ComponentType } from 'react';
 
-export type SidebarSection = 'sessions' | 'agents' | 'commands' | 'providers' | 'git-identities' | 'settings';
+export type SidebarSection = 'sessions' | 'agents' | 'commands' | 'skills' | 'providers' | 'git-identities' | 'settings';
 
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 export type IconComponent = ComponentType<any>;
@@ -32,6 +32,12 @@ export const SIDEBAR_SECTIONS: SidebarSectionConfig[] = [
         description: 'Create and maintain custom slash commands for OpenCode.',
         icon: RiCommandLine,
     },
+    {
+        id: 'skills',
+        label: 'Skills',
+        description: 'Create reusable instruction files for agents to load on-demand.',
+        icon: RiBookLine,
+    },
     {
         id: 'providers',
         label: 'Providers',