Complete TASK-073 provider env runbook

backend/.env.example

@@ -3,6 +3,10 @@ HLL_BACKEND_PORT=8000
 HLL_BACKEND_STORAGE_PATH=/app/data/hll_vietnam_dev.sqlite3
 HLL_BACKEND_ALLOWED_ORIGINS=http://127.0.0.1:8080,http://localhost:8080
 HLL_BACKEND_REFRESH_INTERVAL_SECONDS=120
+HLL_BACKEND_LIVE_DATA_SOURCE=a2s
+HLL_BACKEND_HISTORICAL_DATA_SOURCE=public-scoreboard
+HLL_BACKEND_RCON_TIMEOUT_SECONDS=10
+HLL_BACKEND_RCON_TARGETS=
 HLL_HISTORICAL_CRCON_PAGE_SIZE=50
 HLL_HISTORICAL_CRCON_TIMEOUT_SECONDS=15
 HLL_HISTORICAL_CRCON_DETAIL_WORKERS=8