feat(aircoding): AirCoding V2 baseline — deterministic multi-agent architecture

Forked from OpenCode v1.17.4 with multi-agent system:
- 5 agents: aircoding, scheduler, worker, architect, reviewer
- Deterministic DAG scheduling engine (coordinator_tick)
- Tool whitelists as hard enforcement
- AirCoding validation plugin
- System prompt injection for routing
- V1 requirements: C4 docs, ADR, AGENTS.md, debug-log.md
- Design documents in docs/

packages/core/test/plugin/skill.test.ts

@@ -0,0 +1,32 @@
+import { describe, expect } from "bun:test"
+import { Effect, Layer } from "effect"
+import { AgentV2 } from "@opencode-ai/core/agent"
+import { FSUtil } from "@opencode-ai/core/fs-util"
+import { SkillPlugin } from "@opencode-ai/core/plugin/skill"
+import { SkillV2 } from "@opencode-ai/core/skill"
+import { SkillDiscovery } from "@opencode-ai/core/skill/discovery"
+import { testEffect } from "../lib/effect"
+
+const it = testEffect(
+  SkillV2.layer.pipe(
+    Layer.provide(FSUtil.defaultLayer),
+    Layer.provide(SkillDiscovery.defaultLayer),
+    Layer.provideMerge(AgentV2.locationLayer),
+  ),
+)
+
+describe("SkillPlugin.Plugin", () => {
+  it.effect("registers the built-in customize-opencode skill", () =>
+    Effect.gen(function* () {
+      const skill = yield* SkillV2.Service
+      yield* SkillPlugin.Plugin.effect.pipe(Effect.provideService(SkillV2.Service, skill))
+
+      expect(yield* skill.list()).toContainEqual(
+        expect.objectContaining({
+          name: "customize-opencode",
+          description: expect.stringContaining("opencode's own configuration"),
+        }),
+      )
+    }),
+  )
+})