scaffold: Docker infrastructure — Compose, Nginx, NATS, Dockerfile

4-service stack (PostgreSQL 16, NATS JetStream, Rust API, Nginx),
multi-stage Rust build with dependency caching, wildcard subdomain
routing for public sites, WebSocket support, rate limiting zones.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docker/nats.conf

@@ -0,0 +1,35 @@
+# Corrosion NATS Configuration
+# JetStream enabled for persistent messaging
+
+listen: 0.0.0.0:4222
+
+# JetStream configuration
+jetstream {
+    store_dir: /data
+    max_mem: 256MB
+    max_file: 2GB
+}
+
+# WebSocket listener for frontend real-time updates
+websocket {
+    listen: "0.0.0.0:9222"
+    no_tls: true  # TLS terminated at Nginx/Cloudflare
+}
+
+# HTTP monitoring
+http: 0.0.0.0:8222
+
+# Logging
+debug: false
+trace: false
+logtime: true
+
+# Limits
+max_payload: 8MB  # Support map file transfer metadata
+max_connections: 10000
+
+# Authorization — tokens validated per-connection
+# Plugin and companion agents authenticate with license-specific tokens
+authorization {
+    timeout: 5
+}