j/k, enter, esc and ? on features, with test/keys-<page>.test.ts #10811

On /settings/features, j/k now focus each feature as a row, Enter opens that feature's settings page, and ? opens the help. No new JavaScript; all of it comes from the shared shell. Esc does not return to the list from a feature's page. bun x tsc --noEmit passed, bun scripts/design-lint.ts is clean, and bun scripts/gate.ts printed only the pre-push hook line, so I don't know whether the gate passed. The features tests pass (54, including the new file); I did not run the full suite, since the forge's check does that on push. I did not use the keep_plan tool.

What changed

• src/web/pages/features.ts: featureRow is now a data-nav row linking to /settings/features/<slug>.
• Forms: the Absorb/Un-absorb, Settings and Accept forms moved into the row's after slot, next to the link. That keeps a <form> out of the <a>, so Enter opens the page and never submits anything.
• test/keys-features.test.ts is new. It drives the real rendered page for a declared feature in happy-dom:

- the row markup, with the forms beside the link; - the focus marker, a j/k walk and Enter, which opens /settings/features/radar; - no key acting while a field is focused; - ? opening the help; - Esc on the feature's own page.

What I left out

• Esc: it does not return to the list. The feature page carries the settings section list, which is also navigable rows, so the shell treats it as a list itself. settings/devices behaves the same way, and the test asserts it.
• Forms: the Absorb, Accept and Save forms are not rows. They are reached by Tab and click only.
• Section rows: the settings section rows share the j/k walk, as on every settings page. From a fresh load, j reaches the feature rows after stepping through the sections below "Features".
• Detail page: the feature's detail page (settings fields, feed, schedule) has no row navigation of its own.

To try it: open /settings/features as an admin, press j until a feature has focus, then Enter. Press ? for the help.

Closes #10799

On /settings/features, j/k now focus each feature as a row, Enter opens that feature's settings page, and ? opens the help. No new JavaScript; all of it comes from the shared shell. Esc does not return to the list from a feature's page. bun x tsc --noEmit passed, bun scripts/design-lint.ts is clean, and bun scripts/gate.ts printed only the pre-push hook line, so I don't know whether the gate passed. The features tests pass (54, including the new file); I did not run the full suite, since the forge's check does that on push. I did not use the keep_plan tool.

What changed

• src/web/pages/features.ts: featureRow is now a data-nav row linking to /settings/features/<slug>.
• Forms: the Absorb/Un-absorb, Settings and Accept forms moved into the row's after slot, next to the link. That keeps a <form> out of the <a>, so Enter opens the page and never submits anything.
• test/keys-features.test.ts is new. It drives the real rendered page for a declared feature in happy-dom:

- the row markup, with the forms beside the link; - the focus marker, a j/k walk and Enter, which opens /settings/features/radar; - no key acting while a field is focused; - ? opening the help; - Esc on the feature's own page.

What I left out

• Esc: it does not return to the list. The feature page carries the settings section list, which is also navigable rows, so the shell treats it as a list itself. settings/devices behaves the same way, and the test asserts it.
• Forms: the Absorb, Accept and Save forms are not rows. They are reached by Tab and click only.
• Section rows: the settings section rows share the j/k walk, as on every settings page. From a fresh load, j reaches the feature rows after stepping through the sections below "Features".
• Detail page: the feature's detail page (settings fields, feed, schedule) has no row navigation of its own.

To try it: open /settings/features as an admin, press j until a feature has focus, then Enter. Press ? for the help.