converge-relay: phase 1 — webhook-to-SSE relay server in Go

- Pub/sub broker with fan-out to SSE clients
- POST /webhook — receives Gitea push events, optional HMAC verification
- GET /events — SSE stream of push events
- GET /health — health check endpoint
- Zero external dependencies (stdlib only)
- Docker-based build via goctl wrapper (golang:1.26-alpine)
- systemd unit, README with deployment docs
- Tests: broker pub/sub, slow subscriber drop, ref parsing, signature verification
- 6.0M static binary

converge-relay/converge-relay.service

@@ -0,0 +1,18 @@
+[Unit]
+Description=Converge relay - webhook-to-SSE relay server
+Documentation=https://github.com/jbrechtel/converge
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+ExecStart=%h/.local/bin/converge-relay --listen :8080
+Restart=on-failure
+RestartSec=5
+
+# Set a shared secret for webhook HMAC verification (optional but recommended).
+# Generate with: openssl rand -hex 32
+# Environment=CONVERGE_RELAY_SECRET=your-secret-here
+
+[Install]
+WantedBy=default.target