fix(dashboard): finish lookbook V2 Costs reflow and typed states

[ScriptedAlchemy]

Summary

• Follow-up to the Costs provider-spend attribution slice integrated on feat: TraceDecay V2 delivery (PR8–PR13) + daemon performance, memory, and reliability overhaul #707 as 274392afd8 / b79de0e347 (from the closed #1525). These three commits were on that branch after the integration point and are rebased here onto the current tip.
• Fixes four defects found by driving the production bundle: the query register (range tabs + authority states) collapsed to one row under the grid and hid its chips; the legend never sat beside the chart because the container query was on the container itself; the priced total in the panel header clipped at 320 CSS px; a served usage aggregate with no coverage word read as partial.
• Adds HTTP-level assertions for the typed /api/plugins/savings/models attribution block and its 400 typed refusal.

Costs at 1440 on the V2 shell, 30-day range
Hover inspects codex without changing the query
Scoped provider in the ledger and inspector
320 CSS px

Motivation

The lookbook brief requires 200%-zoom/320 reflow without clipped truth state, a legend that is also the scope control, and typed states that never claim a coverage the wire did not report. All four defects were visible only through the shipped entry point, not the DOM tests.

Changes

• CostsPage.tsx: register is shrink-0; aperture regrouped to spend field (7) · usage (2) · authority (3) / ledger (9) · inspector (3); usage readout breakdown wraps instead of truncating; usageState switches on the aggregate's coverage word (complete → ready, partial → partial, null/other → unknown with the reason); register spend state derived from the ledger.
• ProviderSpendField.tsx: @container on a wrapper, @3xl:flex-row on the child; priced total moved into the field's own header row; chart 280 px with room for the last axis label.
• CostsInspector.tsx, PricingAuthority.tsx: two-column facts so nothing truncates in a 3-column panel.
• stories/fixtures/data.ts: the overview fixture names its aggregate coverage (complete) the way savings_api::provider_usage_overview does.
• tests/dashboard_api_test/savings.rs: unavailable attribution block carries every grouping empty with null revision; range=fortnight answers 400 with the typed empty body naming the rejected window.

Test plan

• npm run typecheck, npm test on this head — 177 files / 1704 tests
• Production-bundle Playwright journey on this head (fixture-backed /api, new V2 shell): 44 checks — range from URL, hover inspects without writing the URL, Enter/Escape scope and clear, arrow/Home/End traversal, visible focus ring, series-as-table names gaps and unpriced buckets, 1440/768/320 and 200% zoom with no page-level overflow, all operable targets ≥ 44 px, reduced motion, typed unavailable attribution, no console/page errors
• cargo test -p tracedecay --features test-transport --test dashboard_api_test savings on this head (passed on the pre-rebase head; rebuild in progress)
• cargo fmt --check; clippy on tracedecay-dashboard-api and the dashboard_api_test target was clean on the pre-rebase head

Gaps

• No HTTP-level test with seeded provider-usage observations; by_provider / by_provider_day are proven at unit level against the real bundled price table and through the browser fixture.
• Concept items with no production authority remain omitted: spend by execution topology, per-provider project counts, per-provider saved tokens, budgets.
• Status-strip authority cells are rendered in the workspace-owned query register; the shell strip was not changed.
• audit-baselines/costs__*.png are stale by design.

Checklist

• CHANGELOG.md — release-please generates it from conventional commits
• No secrets, credentials, or .env files included
• Breaking changes documented — none

_{To show artifacts inline, enable in settings.}

  

[changeset-bot]

⚠️ No Changeset found

Latest commit: 972af75

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[ScriptedAlchemy]

Integrated directly on the #707 branch at da00b45; the full dashboard suite (184 files / 1807 tests) and typecheck pass after conflict reconciliation.