Composer: Enter does not submit a prompt

[robinbraemer]

Observed

On the landing/first-run composer, typing a prompt and pressing Enter does nothing - the status stays "Flect is ready." and no turn starts. Clicking Create with Flect with the identical text submits correctly ("Flect is responding. Cancel is available.").

Reproduced with Playwright against the dev shell (dark, 1440x900):

input.fill('A simple habit tracker for my morning routine');
input.press('Enter');   // -> nothing happens, status unchanged
button.click();          // -> submits

Why it matters

Enter is the first thing every user tries in a chat-style composer, and there is no feedback explaining why nothing happened. This is the very first interaction in the product.

Notes for whoever picks this up

• The e2e suite does use press('Enter') in shapeFirstInterface and passes, so the failing path may be specific to the pre-activation landing composer (deferred activation boundary, ADR 0003) rather than the post-activation one - i.e. the first Enter may be consumed by activation without being replayed as a submit.
• If Enter is intentionally not a submit on this surface (e.g. to allow multi-line entry), then the affordance must say so - but the default expectation for a single-line-looking composer is submit-on-Enter with Shift+Enter for newline.