fix(mobile): update agent-device for iOS toolbar occlusion

[DimaMishchenko]

What and why

• Update agent-device from 0.21.18 to 0.21.20 to include callstack/agent-device#3097, fixing false occlusion of visible controls by sibling-sized iOS toolbar containers.
• Align the docs dependency, regenerate the lockfile, and add a mobile patch changeset.

Verified

Ran it locally: yes

• pnpm check passed; every package test suite passed across local runs (web with one worker).
• Existing iOS consumer interactions and native assertions passed with 0.21.20.

Checklist

• Changeset added for @e2e-dev/mobile.
• Breaking-change requirements: not applicable, no public API change.
• Docs dependency updated; no documented API or skill instructions change.
• Contract/wire-change requirements: not applicable.
• Engine-contract changesets: not applicable, the engine contract is unchanged.

[cubic-dev-ai]

No issues found across 4 files

_{Re-trigger cubic}

[okwasniewski]

thanks!