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/fixture/location.ts

@@ -0,0 +1,12 @@
+import { Location } from "@opencode-ai/core/location"
+import { Project } from "@opencode-ai/core/project"
+import { AbsolutePath } from "@opencode-ai/core/schema"
+
+export function location(ref: Location.Ref, input: { projectDirectory?: AbsolutePath; vcs?: Project.Vcs } = {}) {
+  return {
+    directory: ref.directory,
+    workspaceID: ref.workspaceID,
+    project: { id: Project.ID.global, directory: input.projectDirectory ?? ref.directory },
+    vcs: input.vcs,
+  } satisfies Location.Interface
+}