SaveData and Leaderstat System

Player Data Save System A production-ready save system on DataStoreService. Server-authoritative, with session locking, autosave, retries with backoff, and safe schema upgrades. Features - Session locking: data loads on one server at a time (no duplication or rollbacks); a crashed server's lock expires so another can take over - Never overwrites good data: failed loads kick or retry, never load defaults over a real save - Autosave on interval, on leave, and on shutdown - Schema migration: add a field to the Template and old saves get it automatically; numbered migrations for bigger changes - Leaderstats bridge: list saved fields to show + persist them (Cash included) - Clean API: GetData, a ready callback, safe read/update Requirements: pure Roblox APIs; published place with API access to save. Setup: drag one folder into ServerScriptService; read/write via DataService.