Add telemetry data service and dashboard revamp

Introduce a telemetry data microservice under misc/data: add Dockerfile, entrypoint, migration tools, README, LICENSE and a .gitignore. Increase Docker CACHE_TTL_SECONDS to 300s. Implement extensive dashboard and analytics updates in dashboard.go: add total_all_time and sample_size, return total item counts from fetchRecords (with page/limit handling and a maxRecords guard), raise top-N limits, add a minimum-installs threshold for failed-apps, and numerous UI/style/layout improvements in the embedded DashboardHTML. Minor formatting tweak to misc/api.func.

misc/data/migration/migration.go

@@ -95,13 +95,13 @@ func main() {
 		pbCollection = os.Getenv("PB_TARGET_COLLECTION")
 	}
 	if pbCollection == "" {
-		pbCollection = "_telemetry_data"
+		pbCollection = "telemetry"
 	}
 
 	// Auth collection
 	authCollection := os.Getenv("PB_AUTH_COLLECTION")
 	if authCollection == "" {
-		authCollection = "_telemetry_service"
+		authCollection = "telemetry_service_user"
 	}
 
 	// Credentials - prefer admin auth for timestamp preservation