OpenHands

<@U093U7MJ44B> cookie based cloud BE support: <https://github.com/OpenHands/agent-canvas/pull/1819|github.com/OpenHands/agent-canvas/pull/1819>

When we deploy canvas on cloud via a subpath we automatically get access to the cloud cookie, and this PR enables us to use it as an auth method

Also relatedly more prep where we redirect to the canvas microservice on login (similar to the pr you reviewed for automations microservice)

<https://github.com/OpenHands/OpenHands/pull/15286|github.com/OpenHands/OpenHands/pull/15286>

I've confirmed that these work by QAing here: <https://pr-254.staging.all-hands.dev/canvas|pr-254.staging.all-hands.dev/canvas>

Hello <@U07TE39J96U>,

I've approved the pull request.

Thank you very much! :thankyou:

<@U093U7MJ44B> mind reviewing this pr as well: <https://github.com/OpenHands/OpenHands/pull/15286|github.com/OpenHands/OpenHands/pull/15286>

Hello <@U07TE39J96U>,

I have approved the pull request.

Thank you very much! :thankyou: