revert: remove cache_sync references from sage.py

- Remove 'start_cache_sync' from rbac.init import
- Remove 'add_startup' import
- Remove 'add_startup(start_cache_sync)' call from init()
- This reverts the cache_sync integration that caused session data loss

app/sage.py

@@ -9,8 +9,8 @@ from appPublic.registerfunction import RegisterFunction
 from bricks_for_python.init import load_pybricks
 from ahserver.webapp import webapp
 from ahserver.serverenv import ServerEnv
-from ahserver.configuredServer import add_cleanupctx, add_startup
-from rbac.init import load_rbac, start_cache_sync
+from ahserver.configuredServer import add_cleanupctx
+from rbac.init import load_rbac
 from pricing.init import load_pricing
 from appbase.init import load_appbase
 from llmage.init import load_llmage
@@ -41,7 +41,6 @@ def init():
 	load_pybricks()
 	load_appbase()
 	load_rbac()
-	add_startup(start_cache_sync)
 	load_accounting()
 	load_unipay()
 	load_platformbiz()