feat(scaling): first screen with ladder, ceilings, guardrails and progress

[0x00101010]

Summary

Why

The scorecard's headline was four unrelated cards, so a reader could not see how far observed load sits from the operating point, the binding ceiling, and the configured limit, nor which of those numbers is measured rather than modeled. One axis puts them in proportion and tags each one.

What

• Ladder: one 0–configured-limit axis in Mgas/s with rungs for observed p50/p99, operating point, qualified sustained, the binding ceiling from deriveBinding(ceilings) (named by area, "not modeled" listing every area when none binds), and a grey "configured limit" tick that is never styled as capacity. Rungs without a value are listed beside the axis with their tag, never dropped.
• layoutRungs (pure, unit-tested): sorts rungs by value, alternates sides, drops a label to the next free tier on its side when it would overlap, and anchors labels near the ends so they stay inside the axis. Label width is measured, so 360 px and 1280 px both lay out without overlaps.
• Info: an inline-SVG "i" that opens a popover on hover, keyboard focus, and tap; aria-describedby on the trigger; Escape and outside click close it.
• Translation line under the ladder: 1 Mgas/s ≈ N payments/s ≈ M swaps/s from the snapshot constants, or "constants pending".
• The existing "as of" line and stale banner stay above the ladder; sections and work are unchanged.

Notes

• Stacked on feat(scaling): add ceilings and guardrails to the snapshot #195 (which stacks on feat(scaling): snapshot schema v2 with ladder, ceilings and guardrails #194); the diff here is only the ladder.
• Info uses @base-ui/react/popover rather than the existing InfoTooltip because tooltips do not open on tap or stay open on an outside click.

Screenshots

/scaling on the internal build with invented fixtures (none of these numbers describe a real network).

Crowded fixture, 1280 px:

Crowded fixture, 360 px:

Info popover opened from the keyboard:

All-null fixture (every rung listed beside the axis):

Committed synthetic fixture, now past the 10-day staleness threshold:

Test plan

• npm test, npm run typecheck, npm run lint, npm run build, npm run build:internal, npm run llms -- --check
• Rendered at 360 px and 1280 px with a crowded fixture, an all-null fixture, and the stale committed fixture: zero overlapping label boxes (measured bounding rects), every Info reachable by Tab, popover opens on focus, aria-describedby resolves, Escape closes
• layoutRungs unit tests cover sparse, crowded, tier reuse, end anchoring, and clamping above the limit

Consolidated

This PR now also carries #197 (ceiling cards, guardrails strip, shared Tag) and #198 (progress from Linear, collapsed detail sections). Base is now feat/scaling-schema-v2 (#194). Commits are unchanged; review them in order.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated
omni-ui	Ready	Preview	Oct 16, 2026 1:32pm UTC

[cb-heimdall]

✅ Heimdall Review Status

Requirement	Status	More Info
Reviews	✅ 1/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1