Analyse: Heatmap-Link, Sperre, leere Domains, Tab-Wettlauf

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

server/services/analyse.js

@@ -139,6 +139,7 @@ export async function activateAnalyse({ customerId, projectId, accentColor, cons
     const eligibility = await analyseEligibility(customerId, projectId)
     if (!eligibility.ok) throw httpError(ELIGIBILITY_STATUS[eligibility.reason], ELIGIBILITY_MESSAGES[eligibility.reason])
     const { project } = eligibility
+    if (!analyseDomains(project).length) throw httpError(409, 'Keine gültige Domain für die Analyse')
 
     const existing = await ensureFeatureDoc(customerId, projectId, FEATURE_KEY)
     if (existing.state === 'disabled' && by === 'customer') {