Sign-up pages: UX polish found on dev

Itemized fixes from walking `https://app.dev.jaah.ai/signup?plan=team` at 375 px and 1280 px, light and dark, after PR #6467 deployed. Items 1–6 come from the unparented draft Task 8501, which never dispatches; this task replaces it. 1. Plan cards: a plan named "Free" shows "Free" twice (name and price). Hide the price label when it repeats the name. 2. Plan page: the "Plan" legend repeats the "Choose your plan" heading. Hide it visually and keep it for screen readers. 3. Profile: preselect Country from the browser locale (`navigator.language` region) when nothing is stored. 4. Profile after a provider sign-up: offer "Use a different account", which clears the signup cookie and returns to a fresh /signup. 5. Profile at 375 px: the Organization card's "A company or team" wraps to two lines (observed). Shorten it or tighten the padding so both cards stay one line. 6. Payment page: show a skeleton the size of the Payment Element until Stripe loads, so the layout does not jump. 7. Dark mode: the Google button sits in a white box on the dark card (observed). `apps/web/src/pages/authEntry.tsx:270` always renders GSI with `theme: 'outline'`; use `filled_black` when the console theme is dark, or wrap it so no white edge shows. 8. The Google button is narrower than the GitHub button at 1280 px (400 px vs the full card width; observed). Make both provider buttons one width. 9. A returning visitor whose session has expired is bounced from `/signup?plan=…` to `/login` (observed once on dev). Cause: `apps/web/src/pages/signup/SignupPage.tsx:62` redirects to `/` on the stale `cockpit.auth` localStorage snapshot before `/api/auth/me` answers 401. Redirect only on a confirmed live session. Out of scope: the signup API seam, prices, the trial length, the change-plan wizard, the approval and welcome screens. Done means: - Each item is fixed, or rejected with a one-line reason. - vitest covers 1, 2, 4 and 9 (stale snapshot + 401 `/me` stays on `/signup`). - Screenshots of `/signup` and `/signup/plan` at 375 px and 1280 px, light and dark, in the PR body. - `./dc check quick` green; Jaah Deploy succeeds; dev `/signup?plan=team` checked in a browser.

All 9 sign-up UX items fixed in #6471 and #6476, both merged and deployed. Quick gate, vitest and e2e green; dev /signup?plan=team checked. Visual check done: buttons are one width, there is no bounce on a stale session, and Country comes from the locale. Follow-up draft #8533 filed. Memory: used mem-22518, mem-22588; proposed 1 gotcha.