feat: color latency percentiles by magnitude

[Makisuo]

What

Adds a shared, percentile-aware magnitude→tone scale in @maple/ui and applies it to every P50/P95/P99 value across web and local-ui — services table, operations/dependencies tabs, service-map hover cards + node metric cells, Cloudflare/PlanetScale infra tables, and the chat result renderers (17 call sites).

Fast values recede and slow ones advance, so a percentile column can be scanned instead of read.

	before	after
a healthy 40-row services table	120 identical grey numbers	reads flat/muted; nothing pops
one slow service	looks the same as the rest	its p99 goes amber → red first

Why

P50/P95/P99 rendered as flat, uncolored mono text everywhere. Every cell in a percentile column looked identical, so finding the slow service meant reading every number. Error rate already had per-site tone helpers; latency had none.

How it works

packages/ui/src/lib/latency-tone.ts — pure logic + class maps, a sibling of the existing infra/severity-tokens.ts vocabulary.

• Tone is value ÷ budget(scale), with per-percentile budgets (p50 300ms, avg 500ms, p95 1s, p99 2s, cpu 50ms) rather than one absolute threshold. p99 is expected to exceed p50, so a single threshold would paint every p99 column red; per-budget means a healthy service reads flat across all three.
• The p95 budget's slow/critical boundaries land exactly on P95_DEGRADED_MS / P95_UNHEALTHY_MS from service-health.ts, so a cell tone can't disagree with the health badge on its own row.
• The cpu scale exists because Cloudflare Worker CPU time is ~20× tighter than wall-clock; on the p99 budget every worker collapsed to the quiet step.
• Warm-only 5-step ramp — nothing is colored for being fine: muted → foreground/70 → foreground → severity-warn → severity-error. Reuses existing tokens only; no new design tokens (check:tokens still passes at 148 shared tokens). Tone is never the sole signal — the number carries the meaning and each LatencyValue gets a plain-word title (fast/normal/…/very slow).

packages/ui/src/components/latency-value.tsx — <LatencyValue ms={} scale="p95" />, the ergonomic for the ~90% case (format + tone in one span); latencyToneClass() for sites that already own their element (e.g. service-map MetricCell, stat cards).

Judgment calls a reviewer should check

• A stronger signal wins; the ramp is only the fallback. An open incident/anomaly cause keeps its tone in service-health-section, and the "p95 > 3× this node's own p50" tail check still wins in the service map. Magnitude tone applies only when neither fires.
• quiet is plain text-muted-foreground, not a dimmer opacity variant (the plan said /60). Eyebrow labels beside these values already sit at text-muted-foreground/60; a value fainter than its own label reads as the label. Confirmed monotonic + legible in both themes via getComputedStyle.
• One deliberate behavior change: web's percentile cells now route through the @maple/ui formatLatency, which continues past seconds — a 90s p99 renders 1.5min instead of 90.00s. Also deletes the third private copy of formatLatency that lived inside services-table.tsx.

Testing

• bun typecheck — green across all 32 packages (also re-verified @maple/ui, @maple/web, @maple/local-ui building at this commit in an isolated worktree, i.e. without the unrelated in-flight work that shares my working tree).
• 10 new boundary tests (apps/web/src/lib/latency-tone.test.ts): every level per scale, the service-health threshold agreement, the budgetMs override, and the 0/NaN/Infinity → quiet guard.
• Rendered the real module through the dev server and screenshotted a 7-service ramp in dark and light — fast rows recede, a slow consumer goes amber, a batch job goes red, and a service at 64/180/410ms stays uniformly neutral despite a 6× spread.

Not done

No authenticated pass over the live UI. Local sign-in needs a password, which I don't enter, so these tones haven't been seen against real warehouse data — only against the real module + real stylesheet. /services and a service's Operations tab are the two views to eyeball.

🤖 Generated with Claude Code

---

^{Need help on this PR? Tag @codesmith-bot with what you need. Autofix is disabled.}

[pullfrog]

Your Pullfrog Router balance is exhausted.

You have a card on file but auto-reload is disabled, so runs paused once your balance went past the overdraft buffer.

Top up balance → · Enable auto-reload →

  ^{｜ ⚠️ this action is pinned to a commit SHA, which freezes the cleanup step — switch to @v0 or keep the SHA fresh with Dependabot ｜ Rerun failed job ➔ ｜ View workflow run ｜ via Pullfrog ｜ Using Claude Opus ｜ 𝕏}