feat(builtin-skills): add playwright skill with MCP config and disabled_skills option

- Add playwright as builtin skill with MCP server configuration
- Add disabled_skills config option to disable specific builtin skills
- Update BuiltinSkill type to include mcpConfig field
- Update skill merger to handle mcpConfig from builtin to loaded skills
- Merge disabled_skills config and filter unavailable builtin skills at plugin init
- Update README with Built-in Skills documentation
- Regenerate JSON schema

🤖 Generated with assistance of OhMyOpenCode (https://github.com/code-yeongyu/oh-my-opencode)

src/features/builtin-skills/skills.ts

@@ -1,5 +1,19 @@
 import type { BuiltinSkill } from "./types"
 
-export function createBuiltinSkills(): BuiltinSkill[] {
-  return []
+const playwrightSkill: BuiltinSkill = {
+  name: "playwright",
+  description: "Browser automation with Playwright MCP. Use for web scraping, testing, screenshots, and browser interactions.",
+  template: `# Playwright Browser Automation
+
+This skill provides browser automation capabilities via the Playwright MCP server.`,
+  mcpConfig: {
+    playwright: {
+      command: "npx",
+      args: ["@playwright/mcp@latest"],
+    },
+  },
+}
+
+export function createBuiltinSkills(): BuiltinSkill[] {
+  return [playwrightSkill]
 }