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/models/agent.js

@@ -100,7 +100,7 @@ class Agent extends Model {
 		delete data.tokenHash;
 		return {
 			...data,
-			version: data.version || (data.lastDiscovery && data.lastDiscovery.version) || (data.lastTelemetry && data.lastTelemetry.version) || 'v2.0.0',
+			version: data.version || (data.lastDiscovery && data.lastDiscovery.version) || (data.lastTelemetry && data.lastTelemetry.version) || 'unknown',
 			lastSeen: data.last_seen ? new Date(data.last_seen * 1000).toISOString() : null,
 			connected: !!(liveState && liveState.connected),
 			// "Online" is a live-connection fact, not a stored one. A row with a