feat(customer-portal): redesign plans page cards

[rrader26]

What

Visual redesign of the customer-portal plans page (/customer-portal/:token/plans), which was rendering as a long wall of uneven boxes.

• Interval toggle instead of duplicate cards. Monthly and annual variants of the same tier no longer each get a card. Each product section has a Monthly / Yearly segmented toggle and the grid shows only the selected interval, defaulting to the interval of the customer's active subscription. This cuts the Memory section from 6+ cards to 3. The toggle only renders when the product actually has more than one interval.
• Cards look like standard SaaS pricing tiles. White elevated tiles with hover lift, a hero-sized price, a hairline divider, and a checkmark feature list. The per-product bordered container was dropped so the cards are the only bordered objects on the page.
• Equal-height cards, full-width CTAs pinned to the bottom, so buttons align across a row instead of floating at whatever height the description ended.
• Current plan is marked with a blue ring + "Current plan" chip rather than a filled blue card.
• Prices drop trailing cents on whole amounts ($19 not $19.00), and plan names drop the now-redundant (Annual) suffix.

Notes

• No new translation keys — interval labels reuse the existing getIntervalTranslationKey map from ~/core/constants/form.
• The feature bullets are parsed from plan.description (lead-in, em-dash, comma-separated list). Descriptions that don't fit that shape fall back to a plain paragraph. If we want this durable, the follow-up is a features key in plan metadata.
• No behavior/API changes: same queries, same mutations.

Test plan

• tsc --noEmit and pnpm lint clean
• Visual check on the portal (needs a valid portal token — not verified locally)

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