fix(ui): site-status modal API, honest agent version fallback, Directory default org name

Fresh-install bug report fixes:

- 'Master Site' button error 'app.modal.show is not a function': the
  multi-site status modal used the legacy app.modal.show() signature; the app
  exposes app.modal.open({title, bodyHtml, size}). The site-status request
  itself worked -- only the rendering call was wrong.
- Agents with no discovery yet showed a fake 'v2.0.0' (three hardcoded
  fallbacks). Now 'unknown', so a host whose agent never connected isn't
  presented as an old version.
- The default org name (browser tab title) is set by theta-suite's setup.sh;
  that default is fixed separately there (CFG_ORG -> Theta Directory).

nodejs/utils/agent_manager.js

@@ -118,7 +118,7 @@ class AgentManager {
 
   async handleDiscovery(agent, payload) {
     const discovery = {
-      version: payload.version || payload.agent_version || 'v2.0.0',
+      version: payload.version || payload.agent_version || 'unknown',
       hostname: payload.hostname || '',
       ip_addresses: Array.isArray(payload.ip_addresses) ? payload.ip_addresses : [],
       public_ip: payload.public_ip || '',