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/

.dockerignore

@@ -0,0 +1,12 @@
+.git
+.opencode
+.sst
+.turbo
+.wrangler
+node_modules
+**/node_modules
+**/.output
+**/dist
+**/.turbo
+**/.vite
+**/coverage