feat(debug): add Telemetria teszt section to debug page (v0.28.1)

- New GET /api/debug/telemetry endpoint runs full telemetry pipeline on-demand
- GetTelemetryPreview callback added to DebugCallbacks, wired in main.go
- BuildAppTelemetryForDebug() exported wrapper in report/telemetry.go
- Debug page: new collapsible section with per-app table (memory, CPU, log errors/warnings, issues) and raw JSON viewer
- Available regardless of hub configuration

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

controller/internal/report/telemetry.go

@@ -117,3 +117,10 @@ func buildAppTelemetry(allStacks []stacks.Stack, telemetry []metrics.ContainerTe
 	}
 	return result
 }
+
+// BuildAppTelemetryForDebug runs the full telemetry collection pipeline
+// (metrics query + log scan) and returns per-app telemetry data.
+// Used by the debug endpoint to preview telemetry without pushing to hub.
+func BuildAppTelemetryForDebug(stackMgr *stacks.Manager, metricsStore *metrics.MetricsStore, logger *log.Logger) []AppTelemetry {
+	return buildAppTelemetrySection(stackMgr, metricsStore, logger)
+}