Wrap Starlette's session in an AttrDict

[jbellis]

Testing status:

fasthtml:

• nbdev_test passes except oauth, which also fails without this patch (No such file or directory: '../examples/gh_secret.env')

manually testing fasthtml-examples using sessions:

• todos2: works, including when modified to use attribute syntax
• image_app_session_credits: skipped (requires giving Replicate my billing info)
• data_spot_check: works
• 03_pictionary: No such file or directory: 'multiplayer.css' (same error without this patch)

[gitnotebooks]

Found 1 changed notebook. Review the changes at https://gitnotebooks.com/AnswerDotAI/fasthtml/pull/213

[jbellis]

Also confirmed that home and about work, although neither appears to use sessions.

[jph00]

Thank you! PS: tag me for review, or at-mention me, so I don't miss PRs in the future.

[jph00]

Oh and also - thank you for the careful testing :D

[jbellis]

Thanks, and will do!