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/global.test.ts

@@ -0,0 +1,16 @@
+import { describe, expect, test } from "bun:test"
+import fs from "fs/promises"
+import os from "os"
+import path from "path"
+import { Global } from "@opencode-ai/core/global"
+
+describe("global paths", () => {
+  test("tmp path is under the system temp directory", () => {
+    expect(Global.Path.tmp).toBe(path.join(os.tmpdir(), "opencode"))
+    expect(Global.make().tmp).toBe(Global.Path.tmp)
+  })
+
+  test("tmp path is created on module load", async () => {
+    expect((await fs.stat(Global.Path.tmp)).isDirectory()).toBe(true)
+  })
+})