Nice tight fix for both bugs — the <form onsubmit> pattern is the right way to handle Enter, and opening create directly when knownTags.size === 0 is exactly the UX the issue asked for.

Blocker: missing tests.

This changes behavior in two user-visible ways and web-console has a hard rule (from Gerd) that behavioral changes need tests. Concrete suggestions using Vitest + @testing-library/svelte:

1. Enter submits the create form — render the create panel, type a tag name, userEvent.keyboard('{Enter}'), assert onSubmit was called (or the tag appears in the mock store).
2. Enter is a no-op when submitDisabled is true — same setup with the button in its disabled state (e.g. empty/duplicate name), assert onSubmit was not called.
3. Empty pool skips the search list and opens create directly — render Tags with knownTags = new Set(), click the trigger, assert the create form is visible and the search <input type="search"> is not in the document.
4. Non-empty pool still shows search — render with a couple of tags, click trigger, assert the search input is present.

The reviewer bandwidth is not the issue here — it's that the web-console has zero test coverage and every PR that changes behavior without adding tests locks that in. Please add a Vitest spec next to Tags.svelte.

Minor nit (non-blocking): in the open closure, when knownTags.size === 0 you call openCreate('') and then toggle(). That's fine as long as openCreate doesn't itself toggle — worth a quick check that opening the popup once (not twice) is what happens.

The fix for both issues is minimal, idiomatic, and works as expected. Thank you for the contribution!

Add tests as I mentioned above and you can merge.