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/opencode/test/fixture/config.ts

@@ -0,0 +1,23 @@
+import { Config } from "@/config/config"
+import { emptyConsoleState } from "@opencode-ai/core/v1/config/console-state"
+import { Effect, Layer } from "effect"
+
+export function make(overrides: Partial<Config.Interface> = {}) {
+  return Config.Service.of({
+    get: () => Effect.succeed({}),
+    getGlobal: () => Effect.succeed({}),
+    getConsoleState: () => Effect.succeed(emptyConsoleState),
+    update: () => Effect.void,
+    updateGlobal: (config) => Effect.succeed({ info: config, changed: false }),
+    invalidate: () => Effect.void,
+    directories: () => Effect.succeed([]),
+    waitForDependencies: () => Effect.void,
+    ...overrides,
+  })
+}
+
+export function layer(overrides?: Partial<Config.Interface>) {
+  return Layer.succeed(Config.Service, make(overrides))
+}
+
+export * as TestConfig from "./config"