[Feature Request]: Mobile apps should open docs from affine:// deep links

Description

The Android and iOS apps only handle affine://authentication (SSO / magic link) callbacks. Doc links like the ones desktop opens, for example affine://app.affine.pro/workspace/<ws>/<doc>?server=..., do nothing on mobile. They should open the doc, the same way they do on desktop.

Use case

Linking to docs from other apps on the phone (tasks, chat, shortcuts, automation), and self-hosted setups where https:// links can't be claimed as App Links.

Anything else?

Android only registers the affine scheme. Should canary/beta builds also register affine-canary and affine-beta? PR: #15755.

Drafted with help from an AI coding assistant; the author reviewed it.