Fix service-framework selection and the growing command panel

[DanMat]

Both bugs from using the configurator.

Picking a service framework did nothing

Selecting Express left the command as npx create-packkit my-package -y.

The command builder only emits --server when the service target is selected, and that's correct — the flag is inert without it. The bug is that the control was rendered unconditionally, so clicking Express changed neither the command nor the files, which reads as a broken app.

Options can already declare when they apply, via a when predicate. Nothing honored it. The web configurator now does, so a control that can't affect the output isn't offered at all.

That also fixes a second instance I'd introduced: Monorepo layout shipped in 2.9.0 with a when that was quietly dead code, so it rendered even with monorepo off. The CLI wizard already guarded both cases by hand, so it was correct throughout — the web surface was the inconsistent one.

The command box grew the page

Grid items default to min-width: auto, so an unwrapped 300-character command sets the column's minimum width. .cmd already had overflow-x: auto; it never got the chance to scroll.

Measured in the live page, toggling the fix off and on:

	columns	page scroll width
without min-width: 0	48px / 1534px	1582px (overflows)
with it	720px / 720px	1440px (no overflow)

That 48/1534 split is exactly the squeeze in the report — the form crushed, the preview enormous.

Verified in the browser

• Default state: neither Service framework nor Monorepo layout is shown.
• Select HTTP service → the framework picker appears → Express yields --server express --target library --target service.
• Columns hold 720/720 whether the command is 194 or 303 characters, and .cmd scrolls internally.

49 tests pass, including new ones asserting both when predicates behave.

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