The New forge form offers the size, records it only when it is not the default, and shows an unknown size beside the field #5683

The New forge form now has an optional size select. Small is preselected and sends nothing, so the plan stays as it is today. The four new tests plus test/new-forge.test.ts, test/ssh-site.test.ts and test/spawn-fresh-forks.test.ts pass (29 tests), tsc --noEmit is clean and design-lint passes. I did not run the whole suite.

• Form: /forges/new (src/web/pages/new-forge.ts) has a "Size (optional)" select with small, medium and large, each with its one-line description from sizesView(). It is built with selectField unchanged.
• Recording: medium or large is passed to the plan and ends up in the child's parent.json.
• Unknown size: a posted unknown size re-renders the form with a 422. The message "size must be small, medium or large" sits in a sibling <span class="error" id="f-size-err"> after the select, and every other value is kept. The size is validated in planSpawn, after the other field checks.
• Tests: test/new-forge-size.test.ts covers the four cases.

- Select: present with small chosen. - Small: the post carries no size. - Medium: it reaches parent.json. - Unknown size: a 422 with the message and the kept values. - How "no size" is checked: it spies on spawnDoor's arguments, because the plan page never prints the plan's size.

I did not attach the before-and-after screenshot of the form that the issue asks for; this sandbox can't take one.

To try it, open /forges/new, pick medium, press See the plan, then Spawn.

Closes #5680

The New forge form now has an optional size select. Small is preselected and sends nothing, so the plan stays as it is today. The four new tests plus test/new-forge.test.ts, test/ssh-site.test.ts and test/spawn-fresh-forks.test.ts pass (29 tests), tsc --noEmit is clean and design-lint passes. I did not run the whole suite.

• Form: /forges/new (src/web/pages/new-forge.ts) has a "Size (optional)" select with small, medium and large, each with its one-line description from sizesView(). It is built with selectField unchanged.
• Recording: medium or large is passed to the plan and ends up in the child's parent.json.
• Unknown size: a posted unknown size re-renders the form with a 422. The message "size must be small, medium or large" sits in a sibling <span class="error" id="f-size-err"> after the select, and every other value is kept. The size is validated in planSpawn, after the other field checks.
• Tests: test/new-forge-size.test.ts covers the four cases.

- Select: present with small chosen. - Small: the post carries no size. - Medium: it reaches parent.json. - Unknown size: a 422 with the message and the kept values. - How "no size" is checked: it spies on spawnDoor's arguments, because the plan page never prints the plan's size.

I did not attach the before-and-after screenshot of the form that the issue asks for; this sandbox can't take one.

To try it, open /forges/new, pick medium, press See the plan, then Spawn.

Both blockers are fixed and pushed. The size tests, test/tui-newforge.test.ts, test/new-forge.test.ts, test/ssh-site.test.ts and test/spawn-fresh-forks.test.ts pass, tsc --noEmit is clean and design-lint passes. I didn't run the whole suite.

• Terminal form: src/tui/screens/newforge.ts has a "Size" field after "Follows this forge's code". It goes through the same spawnDoor call with the page's rule: empty or small sends nothing, medium or large is sent. An unknown size shows the door's refusal beside the field. Two new tests in test/tui-newforge.test.ts: medium reaches parent.json, and an unknown size is refused with the message on screen. There is no terminal test that small sends no size; the page test covers that rule.
• selectField error: it now takes error the way field does. data-invalid goes on the .field div, and the select gets aria-invalid and aria-describedby="f-size-hint f-size-err". The error span sits inside the field, and the hint now has an id. The hand-placed span is gone from new-forge.ts. The 422 test checks all of this wiring.
• Label case: the labels now read "small: for a notes app…".
• README: the terminal New forge paragraph and the spawn-size paragraph say both forms offer it.
• selectField callers: I didn't change the select's markup for callers with no hint or error beyond adding the hint id. test/ssh-site.test.ts still passes, as do the other callers' tests that ran. I changed one assertion in my own test/new-forge-size.test.ts, because it matched the old exact <select> tag.

I still haven't attached the before-and-after screenshot of the form; this sandbox can't take one.

I fixed the two failing boards tests and pushed. I did not run the full suite: my full run timed out and gave no result. The boards, size, terminal New forge, ssh-site, web-ui, studio-shipping and webspec tests pass locally.

The cause was the selectField change from the review round, which test/boards-page.test.ts matches on exactly.

• Select tag: the <select> opening tag had been reflowed onto several lines, which broke the check that the chart select has id then name. I put it back as <select class="input" id=… name=…, with the aria attributes on the next line, so that test passes unchanged.
• Hint id: selectField now gives the hint an id so aria-describedby can point at it. The "Column to aggregate" hint check in the same file expected the bare <span class="hint">. I updated that one assertion, because it was over-specific; nothing else about the hint changed.

I also adjusted the select check in test/new-forge-size.test.ts to allow the new line break.