fix: make iOS keyboard dismiss handle common native controls

[thymikee]

Summary

agent-device keyboard dismiss on iOS currently returns UNSUPPORTED_OPERATION when the runner cannot hide the keyboard via its narrow built-in paths. Dogfood exposed a case where agents had to fall back to a visible app control (Done) instead of keyboard dismiss.

Current behavior

The iOS runner currently tries:

• app.keyboards.firstMatch.swipeDown()
• keyboard/toolbar controls labeled Hide keyboard or Dismiss keyboard

If the keyboard remains visible, it returns:

UNSUPPORTED_OPERATION: Unable to dismiss the iOS keyboard without a native dismiss gesture or control

This misses common iOS dismissal controls such as a visible Done toolbar button.

Expected behavior

keyboard dismiss should reliably use common native iOS keyboard dismissal controls when they are exposed and hittable, without requiring agents to manually press app-specific controls first.

Suggested implementation

• Expand tapKeyboardDismissControl in ios-runner/AgentDeviceRunner/AgentDeviceRunnerUITests/RunnerTests+Interaction.swift to include common safe labels such as Done.
• Check toolbar buttons outside app.keyboards where relevant.
• Keep the no-navigation guarantee: do not fall back to back --system behavior inside keyboard dismiss.
• Preserve explicit UNSUPPORTED_OPERATION when no safe native dismiss path is available.

Tests / validation

Add or update tests covering iOS keyboard dismissal when a visible native/app toolbar Done button is available.

Also update guidance after the behavior is fixed:

• agent-device help workflow in src/utils/command-schema.ts
• website/docs/docs/commands.md
• AGENTS.md
• relevant SkillGym guidance cases, especially form-keyboard-dismiss-ios-fallback

The guidance should make keyboard dismiss the preferred iOS path again when the runner can handle common controls, while still documenting fallback behavior for truly unsupported layouts.

[thymikee]

Implemented by #469 (bbb1d363 fix: handle iOS keyboard Done dismiss controls).