fix: align chart date labels with bars

[steipete]

Summary

• center status-menu x-axis date labels on the same tick positions as their bars
• apply the shared alignment convention to cost history, usage breakdown, and plan utilization charts
• add pure slot-geometry regression tests for the first and last labels
• document the fix in the 0.50.1 changelog

Fixes #2974.

Root cause

The bars and axis marks already share the same x values, but the endpoint labels did not share the same horizontal anchor. Cost history and usage breakdown used .topLeading for the first date and .topTrailing for the last date, which placed a label edge at the bar's x coordinate. The label center therefore moved right by half the first label's width and left by half the last label's width. The plan-utilization chart had the same class of workaround as a fixed 24-point left offset on its trailing label.

This replaces those edge-specific adjustments with one centered anchor. Bar data, date domains, day-key conversion, and token/cost values are unchanged.

Tests

• swift test --filter 'ChartAxisLabelLayoutTests|CostHistoryChartMenuViewTests|PlanUtilizationHistoryChartMenuViewTests|UsageBreakdownChartMenuViewTests' — 49 tests passed
• source-blind geometry contract — 2 edge-center checks passed with different localized-label widths
• structured autoreview — clean, no accepted/actionable findings
• make check — passed on the issue branch's original origin/main; after rebasing onto current origin/main, it reaches SwiftLint and fails on the upstream-only UsageStoreWidgetSnapshotTests.swift type-body length (897 > 800). This PR does not modify that file.

[clawsweeper]

🦞👀
ClawSweeper picked this up.

Pull request received. I will update this pull request when review starts.

[clawsweeper]

Codex review: needs changes before merge. Reviewed August 16, 2026, 9:10 AM ET / 13:10 UTC.

ClawSweeper review

What this changes

The branch replaces endpoint-specific date-label anchors in three status-menu charts with a shared centered anchor, adds geometry tests, and updates the changelog.

Merge readiness

⛔ Blocked by patch quality or review findings - 6 items remain

The latest merge commit left both prior coordinate defects unchanged: centering text on day-boundary ticks still leaves Cost History and Usage Breakdown endpoint labels half a slot from their unit: .day bars. Likely related person: steipete (high confidence).

Priority: P2
Reviewed head: c3d87424902537f6b66d5e2fd2abc84eb63ee1c7

Review scores

Measure	Result	What it means
Overall readiness	🦪 silver shellfish (2/6)	The patch is narrowly scoped but retains two prior correctness blockers.
Proof confidence	🌊 off-meta tidepool	Not applicable: This owner-authored PR is not subject to the external contributor proof gate; however, the repository’s UI-patch guidance still supports adding redacted freshly built status-menu evidence after the coordinate fix.
Patch quality	🦪 silver shellfish (2/6)	2 actionable review findings remain.

Verification

Check	Result	Evidence
Real behavior	Not applicable	Not applicable: This owner-authored PR is not subject to the external contributor proof gate; however, the repository’s UI-patch guidance still supports adding redacted freshly built status-menu evidence after the coordinate fix.
Evidence reviewed	5 items	Cost History retains boundary tick values: Bars use point.date with unit: .day, while labels receive unmodified model.axisDates built from first and last day-start dates. Centering text changes label geometry but not the tick coordinate. Usage Breakdown has the same mismatch: Its bars use unit: .day, but the changed centered anchor remains attached to unchanged first/last day tick values. Prior blockers remain unchanged: Both affected file contents hash identically between the prior reviewed head and the current PR head, so these are continued findings rather than late discoveries.
Findings	2 actionable findings	[P2] Move Cost History ticks to day-slot centers [P2] Move Usage Breakdown ticks to day-slot centers
Security	None	None.

How this fits together

Status-menu charts render daily history as bars with sparse x-axis labels. Date labels must use the same horizontal coordinate system as their corresponding bars.

flowchart LR
A[Daily history] --> B[Day-start dates]
B --> C[Day-slot bars]
B --> D[Axis tick positions]
D --> E[Centered labels]
C --> F[Status-menu chart]
E --> F

Loading

Before merge

• Move Cost History ticks to day-slot centers (P2) - barCenteredAnchor only centers the label around model.axisDates, which still holds day-start values. BarMark(..., unit: .day) is centered inside that day slot, so first and last labels remain half a slot left of their bars. Shift these axis values to day-slot centers instead of changing only the label anchor.
• Move Usage Breakdown ticks to day-slot centers (P2) - This has the same unresolved date-axis mismatch: the changed anchor centers text at an unchanged day-boundary tick while unit: .day bars occupy day-slot centers. Use slot-center tick dates so endpoint labels identify the correct bars.
• Resolve merge risk (P1) - Merging now leaves the two daily charts visibly misaligned at their endpoints because their label ticks remain at day boundaries rather than bar-slot centers.
• Complete next step (P2) - The two P2 coordinate fixes are narrow and mechanical; this owner-authored PR must remain open for repair.
• Improve patch quality - Move Cost History and Usage Breakdown ticks to their day-slot centers and extend focused endpoint tests.
• Improve patch quality - Attach a redacted screenshot or recording from a freshly built status menu showing the first and last labels centered under their bars.

Findings

• [P2] Move Cost History ticks to day-slot centers — Sources/CodexBar/CostHistoryChartMenuView.swift:184
• [P2] Move Usage Breakdown ticks to day-slot centers — Sources/CodexBar/UsageBreakdownChartMenuView.swift:94

Agent review details

Security

None.

Review metrics

Metric	Value	Why it matters
Affected chart views	3 chart views changed; 2 retain a day-slot mismatch	A shared anchor is applied across chart types with different x-axis coordinate models.
Code and test delta	production +22/-68; tests +34/-13	Most of the patch removes endpoint workarounds, so endpoint rendering proof remains important.

Merge-risk options

Maintainer options:

1. Correct daily tick coordinates (recommended)
   Move Cost History and Usage Breakdown axis tick values to the same day-slot centers as their bars, then retain the shared centered anchor.

Technical review

Best possible solution:

Use slot-midpoint dates for Cost History and Usage Breakdown endpoint ticks, retain centered anchors, and demonstrate first/last label alignment in the real status menu.

Do we have a high-confidence way to reproduce the issue?

Yes—source inspection establishes the mismatch: daily bars use unit: .day while label ticks remain day-start dates.

Is this the best way to solve the issue?

No—the branch centers text at the existing tick but does not move the tick to the bar’s day-slot center; Plan Utilization’s numeric-index chart does not share this defect.

Full review comments:

• [P2] Move Cost History ticks to day-slot centers — Sources/CodexBar/CostHistoryChartMenuView.swift:184
barCenteredAnchor only centers the label around model.axisDates, which still holds day-start values. BarMark(..., unit: .day) is centered inside that day slot, so first and last labels remain half a slot left of their bars. Shift these axis values to day-slot centers instead of changing only the label anchor.
  Confidence: 0.96
• [P2] Move Usage Breakdown ticks to day-slot centers — Sources/CodexBar/UsageBreakdownChartMenuView.swift:94
  This has the same unresolved date-axis mismatch: the changed anchor centers text at an unchanged day-boundary tick while unit: .day bars occupy day-slot centers. Use slot-center tick dates so endpoint labels identify the correct bars.
  Confidence: 0.96

Overall correctness: patch is incorrect
Overall confidence: 0.96

AGENTS.md: found and applied where relevant.

Codex review notes: model internal, reasoning high; reviewed against 361c9d679c99.

Labels

Label justifications:

• P2: The remaining defect is a visible chart-layout problem with limited user impact.
• merge-risk: 🚨 other: The two daily-chart endpoint labels remain based on day-boundary ticks rather than bar-slot centers.
• rating: 🦪 silver shellfish: Overall readiness is 🦪 silver shellfish; proof is 🌊 off-meta tidepool and patch quality is 🦪 silver shellfish.
• status: ⏳ waiting on author: ClawSweeper has contributor-facing work open and is waiting for author action. Not applicable: This owner-authored PR is not subject to the external contributor proof gate; however, the repository’s UI-patch guidance still supports adding redacted freshly built status-menu evidence after the coordinate fix.

Evidence

Acceptance criteria:

• [P1] swift test --filter 'ChartAxisLabelLayoutTests|CostHistoryChartMenuViewTests|UsageBreakdownChartMenuViewTests|PlanUtilizationHistoryChartMenuViewTests'.
• [P1] make check.

What I checked:

• Cost History retains boundary tick values: Bars use point.date with unit: .day, while labels receive unmodified model.axisDates built from first and last day-start dates. Centering text changes label geometry but not the tick coordinate. (Sources/CodexBar/CostHistoryChartMenuView.swift:184, 3894180aaf8b)
• Usage Breakdown has the same mismatch: Its bars use unit: .day, but the changed centered anchor remains attached to unchanged first/last day tick values. (Sources/CodexBar/UsageBreakdownChartMenuView.swift:94, 3894180aaf8b)
• Prior blockers remain unchanged: Both affected file contents hash identically between the prior reviewed head and the current PR head, so these are continued findings rather than late discoveries. (Sources/CodexBar/CostHistoryChartMenuView.swift:184, c3d874249025)
• Plan Utilization has a distinct valid model: Its numeric x-domain spans half an index before and after the bars, and both bars and labels use the same integer indexes; the centered anchor is appropriate there. (Sources/CodexBar/PlanUtilizationHistoryChartMenuView.swift:541, 361c9d679c99)
• Feature provenance: Current history attributes the daily token chart implementation to the original feature work, while the PR’s source change is commit 3894180. (Sources/CodexBar/CostHistoryChartMenuView.swift:184, 636775c2e2aa)

Likely related people:

• steipete: Current-main history attributes the daily chart implementation to this owner, who also authored the PR’s chart-label change. (role: feature introducer and current chart-area contributor; confidence: high; commits: 636775c2e2aa, 3894180aaf8b; files: Sources/CodexBar/CostHistoryChartMenuView.swift, Sources/CodexBar/UsageBreakdownChartMenuView.swift, Sources/CodexBar/PlanUtilizationHistoryChartMenuView.swift)

Rating scale

Score	Internal tier	Crab rank	Meaning
6/6	S	🦀 challenger crab	Exceptional readiness
5/6	A	🦞 diamond lobster	Very strong readiness
4/6	B	🐚 platinum hermit	Good normal PR; ordinary maintainer review
3/6	C	🦐 gold shrimp	Useful, but confidence is limited
2/6	D	🦪 silver shellfish	Proof or implementation needs work
1/6	F	🧂 unranked krab	Not merge-ready
N/A	NA	🌊 off-meta tidepool	Rating does not apply

Overall follows the weaker of proof and patch quality.
Shiny media proof means a screenshot, video, or linked artifact directly shows the changed behavior. Runtime, network, CSP, and security claims still need visible diagnostics.

Workflow

• ClawSweeper keeps one durable marker-backed review comment per issue or PR.
• Re-runs edit this comment so the latest verdict, findings, and automation markers stay together instead of adding duplicate bot comments.
• A fresh review can be triggered by eligible @clawsweeper re-review comments, exact-item GitHub events, scheduled/background review runs, or manual workflow dispatch.
• PR/issue authors and users with repository write access can comment @clawsweeper re-review or @clawsweeper re-run on an open PR or issue to request a fresh review only.
• Maintainers can also comment @clawsweeper review to request a fresh review only.
• Fresh-review commands do not start repair, autofix, rebase, CI repair, or automerge.
• Maintainer-only repair and merge flows require explicit commands such as @clawsweeper autofix, @clawsweeper automerge, @clawsweeper fix ci, or @clawsweeper address review.
• Maintainers can comment @clawsweeper explain to ask for more context, or @clawsweeper stop to stop active automation.

History

Review history (2 earlier review cycles)

• reviewed 2026-08-16T11:45:51.434Z sha 3894180 :: needs changes before merge. :: [P2] Move date-axis values to day-slot centers
• reviewed 2026-08-16T12:26:21.269Z sha 3dbdf01 :: needs changes before merge. :: [P2] Move date-axis values to day-slot centers | [P2] Align Usage Breakdown ticks with its day bars