feat: add POST /openclaw endpoint and enrich heartbeats with OpenClaw metadata

- Bridge server now accepts POST /openclaw from OpenClaw plugin
- OpenClawMeta struct stores version, plugin_version, and agents
- Heartbeat sendOnce() enriches payload with plugin metadata when available
- Telemetry Payload adds optional openclaw_version field
- README updated to document /openclaw endpoint and metadata enrichment
- All communication remains optional — Monitor functions without plugin data

cmd/harborforge-monitor/main.go

@@ -73,6 +73,19 @@ func main() {
 		// Update bridge with latest telemetry
 		if bridgeSrv != nil {
 			bridgeSrv.UpdatePayload(payload)
+
+			// Enrich payload with OpenClaw metadata if available
+			if meta := bridgeSrv.GetOpenClawMeta(); meta != nil {
+				if meta.Version != "" {
+					payload.OpenClawVersion = meta.Version
+				}
+				if meta.PluginVersion != "" {
+					payload.PluginVersion = meta.PluginVersion
+				}
+				if len(meta.Agents) > 0 {
+					payload.Agents = meta.Agents
+				}
+			}
 		}
 
 		if printPayload || dryRun {