feat: prepare registration-v4 legal contract

[nicoechaniz]

Outcome

Prepares — but does not publish — registration-v4, adding the bilingual disclosure required before CompleteRegistration/Purchase can ship.

The branch is rebased on current main (b62cd9c) and preserves the official inline Ticket Tailor widget, URL normalization/cache busting, checkout identity prefill, bilingual email typo and DNS/MX validation, confirmation content, and the latest registration-page redesign.

Canonical artifacts

• v3 immutable: /legal/terms/registration-v3.html
  • SHA-256 0d65e0c03acd635f08c3e04628a19ef0e674e08612e2ac2446502f3b10b6b54e
• v4 immutable: /legal/terms/registration-v4.html
  • SHA-256 c062b63921bf9a0d175a9770eaeaee647e65347bb3a1188285bc7c3706a1b773
• /politica/ is byte-identical to v4 in this commit.

V4 explicitly discloses the opaque technical Purchase conversion identifier used for deduplication; it remains separate from PII and raw provider IDs.

Behavior and compatibility

• form submits terms_version=registration-v4;
• browser keys are version-scoped to avoid v3/v4 idempotency payload reuse;
• confirmation still reads valid v3 status contexts after cutover;
• consent notice and policy describe PageView, canonical CompleteRegistration and paid-only Purchase, plus explicit non-PII boundaries;
• local build includes policy and immutable legal artifacts.

Coordination required

The current Bot accepts one configured terms version. This PR must remain draft until Mariano deploys the exact allowlisted v3+v4 compatibility contract described in docs/registration-v4-cutover.md, or registration is explicitly closed for an atomic cutover. Never deploy one side alone while registration is open.

Verification

• 29/29 tests
• build green
• diff-check green
• source and dist/ hashes verified byte-for-byte

Closes no issue yet. Related: #12, SairaAsua/proyecciones-mito#33.

[nicoechaniz]

Hash v4 final actualizado tras explicitar el identificador opaco de conversión usado para deduplicar Purchase: c062b63921bf9a0d175a9770eaeaee647e65347bb3a1188285bc7c3706a1b773. El hash v3 permanece sin cambios. Aún no publicado.

[nicoechaniz]

Rebased onto current landing main f7237ca after PRs #24–#26 and the latest registration-page redesign. The rebased diff preserves the official inline Ticket Tailor widget, removes only widget/modal_widget flags, keeps the cache-busted asset, and remains clean/mergeable. Verification on head 4f0b0d3: 25/25 tests, build, diff-check, and exact source/dist hashes pass.

[nicoechaniz]

Rebased onto current landing main 5bdfde4. Head 8b6dd6c preserves the official inline widget, duplicate-flag normalization, cache busting, Ticket Tailor identity prefill, email-domain typo validation, current confirmation pages and the latest visual/content work. Verification: 27/27 tests, build, diff-check and byte-exact v3/v4 source/dist hashes pass.

[nicoechaniz]

Actualización por cambios concurrentes de Mariano/Sai: rebase limpio sobre main@b62cd9c (incluye validación MX #29). Nuevo head 5ef1005. Gates: 29/29 tests, build y diff-check verdes. Se preservan widget inline, prefill, validación tipográfica/MX y los hashes byte-exactos v3/v4. Sigue draft hasta coordinar el corte backend v4.

[Mar-IA-no]

Coordinación de supersesión: el contenido funcional de este stack fue reaplicado sobre el main vigente, preservando la autoría de Nico, revisado y publicado mediante PR #35 (merge 107bb44). La implementación publicada conserva registration-v4, verificación de buzón compatible, CompleteRegistration deduplicado y consentimiento Meta. Para evitar trabajo duplicado, por favor cerrá esta PR apilada; no modificaremos ni eliminaremos su rama. Cualquier evolución posterior debe partir del main actual.