UI polish noticed while testing Task 7092

Noticed on a local stack at 1366px and 390px while verifying Task 7092. 1. An unknown settings URL such as `/settings/billing` silently lands a tenant admin on `/welcome` and an operator on the Dashboard. Redirect it to the real page (`/org/billing`), or show a "Page not found" with a link. 2. Project side pane (Directory, 1366px): the Cancel/Save action bar ends ~60px short of the pane's right edge, while the rows above (Add repository, the repo table's ⋯) reach it. Align Save with the content's right edge. 3. Billing › Payments/Methods/Details with Stripe not connected show only "Billing isn't set up yet" in a full-width card. Say what to do next or who sets it up, as the setup wizard's "Ask the platform operator…" line does. 4. Phone project page (390px): only General, Access and Governance fit before More, out of 8+ tabs. Consider the wrapped strip used on Billing › Products (`wrapOnPhone`) so the common tabs stay one tap away. Out of scope: budgets (Task 6740/7098); the onboarding bar behaviour changed in Task 7092. Done means: - Each item fixed or explicitly rejected with a reason, checked visually at desktop and ≤480px width.

All 4 fixed, checked at 1366/390px: unknown URL shows "Page not found" + Go home in shell; pane Save reaches content edge (launcher seat only when bar is in its row); billing says ask platform operator; phone project tabs wrap. PR #5799 merged by lane; deploy superseded. Follow-up draft #7127.