chore(deploy): enable DEMO_MODE on Cloud Run so the live demo button works

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

Author: HR-coding

deploy-cloudrun.ps1

@@ -61,7 +61,7 @@ gcloud builds submit --tag $img
 if ($LASTEXITCODE -ne 0) { Write-Host "BUILD FAILED - see errors above." -ForegroundColor Red; exit 1 }
 
 Write-Host "== Deploying to Cloud Run ==" -ForegroundColor Cyan
-gcloud run deploy $Service --image $img --region $Region --allow-unauthenticated --min-instances 1 --max-instances 1 --memory 1Gi --set-env-vars "MONGODB_DB=tax_agent_db,ORCHESTRATOR_MODEL=gemini-2.0-flash,AGENT_REQUIRE_SIGNATURE=0,POSTGRES_URL=sqlite+pysqlite:////app/taxassist.db,GOOGLE_CREDENTIALS_FILE=/secrets/cred/credentials.json,GOOGLE_TOKEN_FILE=/secrets/tok/token.json" --set-secrets "MONGO_URI=MONGO_URI:latest,GOOGLE_API_KEY=GOOGLE_API_KEY:latest,AGENT_SECRET_KEY=AGENT_SECRET_KEY:latest,CONTROL_ENC_KEY=CONTROL_ENC_KEY:latest,POLL_TOKEN=POLL_TOKEN:latest,GOOGLE_OAUTH_CLIENT_ID=GOOGLE_OAUTH_CLIENT_ID:latest,GOOGLE_OAUTH_CLIENT_SECRET=GOOGLE_OAUTH_CLIENT_SECRET:latest,/secrets/cred/credentials.json=google-credentials:latest,/secrets/tok/token.json=google-token:latest"
+gcloud run deploy $Service --image $img --region $Region --allow-unauthenticated --min-instances 1 --max-instances 1 --memory 1Gi --set-env-vars "MONGODB_DB=tax_agent_db,ORCHESTRATOR_MODEL=gemini-2.0-flash,AGENT_REQUIRE_SIGNATURE=0,DEMO_MODE=1,POSTGRES_URL=sqlite+pysqlite:////app/taxassist.db,GOOGLE_CREDENTIALS_FILE=/secrets/cred/credentials.json,GOOGLE_TOKEN_FILE=/secrets/tok/token.json" --set-secrets "MONGO_URI=MONGO_URI:latest,GOOGLE_API_KEY=GOOGLE_API_KEY:latest,AGENT_SECRET_KEY=AGENT_SECRET_KEY:latest,CONTROL_ENC_KEY=CONTROL_ENC_KEY:latest,POLL_TOKEN=POLL_TOKEN:latest,GOOGLE_OAUTH_CLIENT_ID=GOOGLE_OAUTH_CLIENT_ID:latest,GOOGLE_OAUTH_CLIENT_SECRET=GOOGLE_OAUTH_CLIENT_SECRET:latest,/secrets/cred/credentials.json=google-credentials:latest,/secrets/tok/token.json=google-token:latest"
 
 if ($LASTEXITCODE -eq 0) {
   Write-Host ""