[Fix] Show missing environment recovery in Custom Automations

[roomote-roomote]

​Opened on behalf of @daniel-lxs. Follow up by mentioning @roomote-roomote, in the web UI, or in Telegram.

What changed

Custom Automation creation and editing now keeps a missing Preferred environment error beside the field instead of showing only a toast. The select receives the existing accessible invalid-field treatment, focus and scroll to the field on submit, and clears the error as soon as an environment is selected.

Why this change was made

Submitting a valid name and prompt without an environment previously left the dialog unchanged except for a transient Choose an environment. toast, making the required recovery control easy to miss. The change follows the existing Name, Prompt, and schedule validation pattern without changing valid payloads or destination behavior.

Impact

People can see exactly which required field needs attention, keyboard and assistive-technology users receive an associated error description, and correcting the selection proceeds through the existing create/edit flow. Focused client coverage verifies the blocked submit, accessibility state, correction clearing, and unchanged valid environment payload.

Authenticated local proof covered the genuine desktop and mobile dialog states, creation and edit persistence with the seeded Roomote Demo Environment, and cleanup of the disposable automation. Visual proof:

[roomote-community]

No code issues found. See task

_{Reviewed 9a9b976}

[daniel-lxs]

Verified field focus and associated validation, immediate error clearing, draft preservation, clean dialog reopening, and create/edit persistence through a browser reload on the exact head. Desktop/mobile inspection, 64 focused tests, web typecheck, scoped lint, and formatting passed.