package:stem_flutter_sqlite v0.3.0

• Added real SQLite coverage for core bounded callbacks: persisted batch
  execution, deferred tasks, cancellation, admission deadlines, and reopening.
• Added StemFlutterSqlite.createApp, returning a real core StemApp backed by
  managed local stores, with one StemFlutterSqliteConfig for storage settings.
• Required Stem >=0.4.1 <0.5.0, stem_flutter >=0.3.0 <0.4.0, and
  stem_sqlite >=0.2.2 <0.3.0 for the shared application surface and safe
  consumer teardown.
• Re-exported Flutter and stable Stem APIs for ordinary task/module usage.
• Breaking: Removed the legacy producer runtime, worker launcher, worker
  stores, and bootstrap payload. Core StemApp owns execution and store
  lifecycles.
• Reuse core factories for manually supplied stores and Ormed data sources.
• Moved required Flutter/Ormed dependency setup here from stem_flutter.
  createApp initializes it automatically; manual integrations can call
  StemFlutterSqlite.initialize.
• Reject path traversal in application directory and helper file names; explicit
  layouts remain available for custom paths.
• Migrated the mobile example and documentation away from manual worker protocols.