chore: drop retired orb and sun VMs

Only the zap VM remains in the fleet. Remove orb/sun from the README
architecture/config docs, the getVMClassName allowlist, and their
.timeline-vm-tag color styles.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

README.md

@@ -7,7 +7,7 @@ Telemetry and monitoring system for AI agent activity across [OpenClaw](https://
 ```
                          ┌──────────────────────────┐
                          │   OpenClaw VMs            │
-                         │   (zap, orb, sun)         │
+                         │   (zap)                   │
                          │                           │
                          │   hooks/agentmon/         │
                          │     → handler.ts          │
@@ -187,7 +187,7 @@ The hook is deployed to each VM at `~/.openclaw/hooks/agentmon/`. Two environmen
 
 ```bash
 AGENTMON_INGEST_URL=http://192.168.122.1:8080
-AGENTMON_VM_NAME=zap  # or orb, sun
+AGENTMON_VM_NAME=zap
 ```
 
 Deployment is automated via Ansible — see the [swarm ansible playbook](https://gitea-http.taildb3494.ts.net/will/swarm) `playbooks/customize.yml`.