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/

infra/stage.ts

@@ -0,0 +1,21 @@
+export const domain = (() => {
+  if ($app.stage === "production") return "opencode.ai"
+  if ($app.stage === "dev") return "dev.opencode.ai"
+  return `${$app.stage}.dev.opencode.ai`
+})()
+
+export const zoneID = "430ba34c138cfb5360826c4909f99be8"
+export const awsStage = $app.stage === "production" ? "production" : "dev"
+export const deployAws = $app.stage === awsStage
+
+new cloudflare.RegionalHostname("RegionalHostname", {
+  hostname: domain,
+  regionKey: "us",
+  zoneId: zoneID,
+})
+
+export const shortDomain = (() => {
+  if ($app.stage === "production") return "opncd.ai"
+  if ($app.stage === "dev") return "dev.opncd.ai"
+  return `${$app.stage}.dev.opncd.ai`
+})()