Summary by Sourcery

Prevent background update scheduler tasks from leaking and adjust web app configuration defaults.

Bug Fixes:

• Ensure the session updates scheduler runs as a single tracked asyncio task that is cancelled when the session closes, avoiding orphaned tasks and memory leaks.
• Handle cancellation cleanly in the updates scheduler loop to prevent spurious errors on shutdown.

Enhancements:

• Promote garbage-collection log messages for sessions and FletApp instances from debug to info for better observability in production.

Deployment:

• Update example Fly.io app configurations to use FLET_FORCE_WEB_SERVER instead of FLET_FORCE_WEB_VIEW in the environment.