A test pins Usage › Spend as a forge admin's: a guest is asked to sign in and anyone else is told not found #6887

test/spend-tab.test.ts now pins Usage › Spend (/settings/spend) as a forge admin's page. It is a test only, with no source change. The three tests pass and the type check is clean. I did not run design-lint, since nothing in src/web/ changed.

• Guest: /settings/spend redirects to /signin?next=%2Fsettings%2Fspend, and the response carries no figure.
• Signed-in non-admin: bob, who owns an app with seeded spend, gets a 404 not-found page. It has no $12.34, no credential name and no Spend heading. I did not assert that the app name is absent, because the not-found page's command palette lists the user's own repositories.
• Forge admin: /settings/spend returns 200 with the Spend heading, the credential work-plan, the app bob/ledger-app and $12.34. The spend phase is in Server-Timing.

• Wall clock: spendPage reads new Date() itself, so now can't be passed in. The test pins the clock with setSystemTime and restores it afterwards, so it never reads the real time.
• Repo seeding: bob's repository is created through core createRepo. The action-level createRepo refused with not_member, because it needs the make-it-yours ability. That ability has nothing to do with this page.

Closes #6856

test/spend-tab.test.ts now pins Usage › Spend (/settings/spend) as a forge admin's page. It is a test only, with no source change. The three tests pass and the type check is clean. I did not run design-lint, since nothing in src/web/ changed.

• Guest: /settings/spend redirects to /signin?next=%2Fsettings%2Fspend, and the response carries no figure.
• Signed-in non-admin: bob, who owns an app with seeded spend, gets a 404 not-found page. It has no $12.34, no credential name and no Spend heading. I did not assert that the app name is absent, because the not-found page's command palette lists the user's own repositories.
• Forge admin: /settings/spend returns 200 with the Spend heading, the credential work-plan, the app bob/ledger-app and $12.34. The spend phase is in Server-Timing.

• Wall clock: spendPage reads new Date() itself, so now can't be passed in. The test pins the clock with setSystemTime and restores it afterwards, so it never reads the real time.
• Repo seeding: bob's repository is created through core createRepo. The action-level createRepo refused with not_member, because it needs the make-it-yours ability. That ability has nothing to do with this page.