feat: add GitHub skill installation support

- Implemented functionality to install skills from GitHub URLs.
- Updated API to handle new installation requests from GitHub.
- Enhanced UI to allow users to input GitHub skill URLs for installation.
- Added translations for new GitHub installation features in English, Thai, and Chinese.
- Created tests for the new skill installation service and API routes to ensure proper functionality.

tests/skills-api.test.ts

@@ -0,0 +1,53 @@
+// @vitest-environment node
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+
+const mocks = vi.hoisted(() => ({
+  hostApiFetch: vi.fn(),
+  gatewayRpc: vi.fn(),
+}));
+
+vi.mock('../src/lib/host-api', () => ({
+  hostApiFetch: mocks.hostApiFetch,
+}));
+
+vi.mock('../src/lib/gateway-client', () => ({
+  gatewayRpc: mocks.gatewayRpc,
+}));
+
+import { apiGetSkillsDir, apiInstallSkill } from '../src/lib/skills-api';
+
+describe('skills api helpers', () => {
+  beforeEach(() => {
+    mocks.hostApiFetch.mockReset();
+    mocks.gatewayRpc.mockReset();
+  });
+
+  it('falls back to ~/.openclaw/skills when the host path request fails', async () => {
+    mocks.hostApiFetch.mockRejectedValue(new Error('offline'));
+
+    await expect(apiGetSkillsDir()).resolves.toBe('~/.openclaw/skills');
+  });
+
+  it('posts unified install requests to /api/skills/install', async () => {
+    mocks.hostApiFetch.mockResolvedValue({
+      success: true,
+      slug: 'minimax-xlsx',
+      baseDir: 'C:/Users/Administrator/.openclaw/skills/minimax-xlsx',
+      source: 'github-url',
+      enabled: true,
+    });
+
+    await expect(apiInstallSkill({
+      kind: 'github-url',
+      url: 'https://github.com/MiniMax-AI/skills/blob/main/skills/minimax-xlsx/SKILL.md',
+    })).resolves.toMatchObject({
+      success: true,
+      slug: 'minimax-xlsx',
+      source: 'github-url',
+    });
+
+    expect(mocks.hostApiFetch).toHaveBeenCalledWith('/api/skills/install', expect.objectContaining({
+      method: 'POST',
+    }));
+  });
+});