fix(backend): never run seed.py in production

entrypoint.sh now requires RUN_SEED=true to execute the seed script.
Without it, only 'flask db upgrade heads' runs on container start.

docker-compose.yml (dev) sets RUN_SEED=true and RUN_CSV_IMPORT=true
so local development behaviour is unchanged.

Production (docker-compose.prod.yml) does not set these variables,
so the database is no longer wiped on every deploy.

backend/entrypoint.sh

@@ -16,11 +16,17 @@ done
 echo "==> Rodando migrações..."
 uv run flask db upgrade heads
 
-echo "==> Executando seeder (idempotente)..."
-uv run python seeds/seed.py
+if [ "${RUN_SEED:-false}" = "true" ]; then
+  echo "==> Executando seeder (RUN_SEED=true)..."
+  uv run python seeds/seed.py
+else
+  echo "==> Seeder ignorado em produção (RUN_SEED não definido)."
+fi
 
-echo "==> Importando imóveis do CSV (idempotente)..."
-uv run python seeds/import_from_csv.py
+if [ "${RUN_CSV_IMPORT:-false}" = "true" ]; then
+  echo "==> Importando imóveis do CSV (idempotente)..."
+  uv run python seeds/import_from_csv.py
+fi
 
 echo "==> Iniciando servidor Flask..."
 exec uv run python run.py