Fix emails plan advisor ranges pricing in NewPlanSelection

[jhoffman-ms]

Related

• Issue/task: not provided

Source of truth

• SPEC: docs/specs/SPEC_20260518_plan-envios-picture-13.md
• This PR also updates that SPEC to explicitly cover the A medida* / Tailored* main-price state for the Emails plan advisor scenarios.

Relevant assets

• docs/assets/picture_14.png
• docs/assets/picture_15.png
• Reference image shared in the task for the expected price/CTA block

What changed

• Updated NewPlanSelection/EmailsPlan so that selecting Menos de 100.000 or Más de 10.000.000 switches the main price block to the commercial state:
  • price label stays the same
  • price value becomes A medida* / Tailored*
  • main CTA stays as Contactar a Asesor / Contact an Advisor
• Hid the extra-email-price line in those commercial scenarios so the card matches the tailored-price layout.
• Kept the sticky summary behavior unchanged in those scenarios, preserving the standard plan summary with commercial CTA as defined by the existing flow.
• Added test coverage for both special Emails-plan ranges to assert the tailored-price state and hidden extra-email-price copy.
• Updated the spec so the main-card tailored-price behavior is explicitly documented for both downgrade (< 100.000) and high-volume (> 10.000.000) states.

How it was tested

• yarn test:related -- src/components/BuyProcess/NewPlanSelection/index.test.js src/components/BuyProcess/NewPlanSelection/EmailsPlan/index.js
• yarn prettier-check

Open questions / follow-up

• None for this change. The spec now matches the implemented UI behavior.