Syncs the fork with upstream v0.7.1 (deployed on pds.wisp.place since 2026-10-20 23:28Z as 0.7.1-wisp.8b897ae).

• Merge of tag v0.7.1 (7aaa931). The reason is upstream's webpki-roots / webpki-root-certs 1.0.10 and rustls-webpki 0.103.16 bump for the eMudhra intermediate CA compromise. Conflicts, all resolved keeping both sides:
  • authorize/{login,mod,passkey,two_factor}.rs: upstream's respond!() wrapper and second-factor flow, with the fork's ?sso= forwarding and current_device() (device retention) carried through.
  • tranquil-store metastore/oauth_ops.rs, tests/it/store_parity.rs: the fork's device helpers and stale-device sweep test kept next to upstream's completed-identity guard.
  • Frontend api.ts, registration/flow.svelte.ts, Register.svelte: the fork's single sign-up form and Turnstile, with upstream's requestUri binding and login_required handling ported in; upstream's did:web/BYOD signup paths stay out, as before.
  • All 10 fork commits are unchanged (git range-diff).
• 8b897ae drops upstream's subscribeRepos rate limit (5 per 60 s per IP), at Ana's request; other limits stay.

Checks: cargo check --all-targets and clippy -D warnings clean; svelte-check 0 errors; vitest 257/257; vite build ok. tranquil-store nextest on a loaded laptop: the gauntlet stress tests exceeded their wall-clock budgets (9) or timed out (5); a comparison against plain v0.7.1 is still pending.