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
- V1 requirements: C4 docs, ADR, AGENTS.md, debug-log.md
- Design documents in docs/

.github/workflows/notify-discord.yml

@@ -0,0 +1,14 @@
+name: notify-discord
+
+on:
+  release:
+    types: [released] # fires when a draft release is published
+
+jobs:
+  notify:
+    runs-on: blacksmith-4vcpu-ubuntu-2404
+    steps:
+      - name: Send nicely-formatted embed to Discord
+        uses: SethCohen/github-releases-to-discord@24d166886aee4646d448c8a389ff9e1ebcab3682 # v1.20.0
+        with:
+          webhook_url: ${{ secrets.DISCORD_WEBHOOK }}