refactor(opencode): restructure config and replace legacy plugins

Rewrites opencode.json, drops the with-context, websearch and terminal-bell
plugins, adds plugins that strip Claude-only commands and OMC MCP servers,
and vendors the impeccable, web-design-guidelines and frontend-workflow skills.

.config/opencode/tests/claude-only-command-registry.test.ts

@@ -0,0 +1,35 @@
+import { describe, expect, test } from "bun:test"
+
+import {
+  CLAUDE_ONLY_COMMAND_RULES,
+  isClaudeOnlyCommand,
+} from "../plugin/lib/claude-only-command-registry"
+
+describe("claude-only command registry", () => {
+  test("matches every prefix rule with a representative command", () => {
+    expect(isClaudeOnlyCommand("oh-my-claudecode:ultrawork")).toBe(true)
+    expect(isClaudeOnlyCommand("claude-notifications-go:settings")).toBe(true)
+  })
+
+  test("matches every exact rule", () => {
+    expect(isClaudeOnlyCommand("remember:doctor")).toBe(true)
+    expect(isClaudeOnlyCommand("mcp-server-dev:build-mcpb")).toBe(true)
+  })
+
+  test("preserves cross-client commands and near misses", () => {
+    expect(isClaudeOnlyCommand("remember:remember")).toBe(false)
+    expect(isClaudeOnlyCommand("mcp-server-dev:build-mcp-server")).toBe(false)
+    expect(isClaudeOnlyCommand("mcp-server-dev:build-mcp-app")).toBe(false)
+    expect(isClaudeOnlyCommand("superpowers:brainstorming")).toBe(false)
+    expect(isClaudeOnlyCommand("chrome-devtools-mcp:chrome-devtools")).toBe(false)
+    expect(isClaudeOnlyCommand("oh-my-claudecode")).toBe(false)
+    expect(isClaudeOnlyCommand("remember:doctor-notes")).toBe(false)
+  })
+
+  test("requires a non-empty reason for every rule", () => {
+    expect(CLAUDE_ONLY_COMMAND_RULES.length).toBeGreaterThan(0)
+    for (const rule of CLAUDE_ONLY_COMMAND_RULES) {
+      expect(rule.reason.trim().length).toBeGreaterThan(0)
+    }
+  })
+})