feat(web): show advisory daily usage budget alerts

[saphid]

The Usage page now shows advisory daily budget levels for Claude API-rate estimates and total API-equivalent usage. These warnings make the existing daily spend visible without blocking provider work.

Split from #8857 at the author's request so handovers and work admission controls remain separate reviews. Budget thresholds and calculations are preserved from the original feature.

Validation at 121268db4: all five focused budget tests pass; scoped web-workspace export analysis (vp exec knip --workspace apps/web --exports --preprocessor ./scripts/knip-schemas.ts --no-config-hints), targeted lint, and diff checks pass. The export check reproduced the CI failure before the fix; the thresholds are now module-local. Earlier feature validation reported a passing web typecheck; it was not rerun for this export-only repair. The real web Usage page shows the warning for synthetic Claude usage of $600 on Sep 5 against its $500 level. The same provider logs produce the same $662 range total on the baseline without the warning. These levels are advisory; no provider pausing is claimed.

Before: the same usage has no daily warning.

After: daily Claude usage crosses its warning level.

Matched content crops omit differing sidebar fixtures and an unrelated update notification on the far right.

Web evidence uses disposable synthetic data: baseline 39802c0, integrated candidate 0cb918039d4f0f220470673e2252acf28eda8d71 (tree f56dc89e078c9ad43ef049202bbb0b428fca2ca4) containing #8857, #10095, #10097 and #10094. This is integrated web proof, not a standalone or native-client capture. It predates the current rebased head; the export-only repair does not alter the shown UI, but these captures are not a fresh current-head interaction run. The prior integration passed 330 focused tests and server/web/React Native typechecks; the candidate differs only in the corrected hard-limit setting description, which passed scoped lint. No unpublished integration glue is required.

Direct Claude Opus 5 high review attempt exited 1 on expired OAuth before a model ran. A fresh direct Claude Opus 5 high review attempt for the export-only repair also exited 1 on expired OAuth; no model ran. Parent source review of that one-line repair found no actionable findings.

Implemented and verified with GPT-6 Astra in the Codex harness.

Note

Add advisory daily usage budget alerts to UsagePage

• Evaluates the selected usage window against daily budget thresholds and renders the strongest returned level (warning, approval, or pause) as an alert in the regular usage view
• Uses separate messaging for Claude and API-equivalent usage, displaying the measured value, threshold, and day along with level-specific review guidance
• Suppresses the alert in the limits view, while usage is pending, or when no threshold is crossed
• Risk: alert rendering depends on the budget evaluator contract; mismatched threshold or level shapes from the evaluator will cause the alert to silently not render or display incomplete guidance in UsagePage.tsx

^{Macroscope summarized 121268d.}

Summary by CodeRabbit

• New Features

  • Added daily usage budget alerts for Claude and API-equivalent costs.
  • Alerts indicate warning, approval, or pause thresholds and include the affected usage date and value.
  • The strongest applicable alert is shown above the usage breakdown.
  • Alerts provide guidance without automatically blocking provider activity.

• Documentation

  • Added user documentation describing daily budget thresholds, alert levels, and advisory behavior.

[macroscopeapp]

Approvability

Verdict: Not approved

Macroscope's review found this PR not approvable — This PR adds an automatically enabled usage-budget alert capability to the production Usage page, including new threshold policy and guidance about expanding or pausing work. The change is localized and advisory, but its new user-facing behavior and spending-related messaging warrant human review.

^{You can add or adjust custom eligibility rules. Learn more.}

[coderabbitai]

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ℹ️ Recent review info

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📥 Commits

Reviewing files that changed from the base of the PR and between 51b5b84 and 121268d.

📒 Files selected for processing (1)

• apps/web/src/components/usage/usageBudget.ts

🚧 Files skipped from review as they are similar to previous changes (1)

• apps/web/src/components/usage/usageBudget.ts

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📝 Walkthrough

Walkthrough

The change adds daily usage budget evaluation for Claude and API-equivalent costs. The usage page displays level-specific alerts for the current day, with tests for threshold selection and day matching. Documentation describes the thresholds and non-blocking behavior.

Changes

Daily usage budget alerts

Layer / File(s)	Summary
Budget evaluation and validation apps/web/src/components/usage/usageBudget.ts, apps/web/src/components/usage/usageBudget.test.ts	Defines thresholds and alert types, evaluates crossings for the requested day, and tests alert selection and date handling.
Usage page alert integration apps/web/src/components/usage/UsagePage.tsx	Computes the current-day alert and renders level-specific guidance for Claude or API-equivalent usage.
Usage budget documentation docs/user/usage.md	Documents calendar-day scope, thresholds, alert levels, and non-blocking behavior.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Merge Risk: ⚪ Minimal · up to 12126

The change adds non-blocking daily usage budget warnings on the Usage page. No concrete merge-blocking risk remains in the supplied change context.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 25.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 4 functions across 3 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly and concisely describes the primary change: adding advisory daily usage budget alerts to the web application.
Description check	✅ Passed	The description explains the change, rationale, UI behavior, validation, test evidence, and screenshots. It does not use the template headings or include the checklist, but it provides the required in…

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[coderabbitai]

Actionable comments posted: 1

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Inline comments:
In `@apps/web/src/components/usage/usageBudget.ts`:
- Line 3: Make DAILY_USAGE_BUDGET module-local by removing its public export,
while preserving the constant and its existing usage within the module.

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Configuration used: Path: .coderabbit.yaml

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📥 Commits

Reviewing files that changed from the base of the PR and between a37c664 and 51b5b84.

📒 Files selected for processing (4)

• apps/web/src/components/usage/UsagePage.tsx
• apps/web/src/components/usage/usageBudget.test.ts
• apps/web/src/components/usage/usageBudget.ts
• docs/user/usage.md

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[saphid]

Friendly review nudge @juliusmarminge @maria-rcks — this is mergeable and hasn't had a maintainer pass yet. Independent bot/agent reviews have run with findings triaged in-commit (see receipts in earlier comments). Full queue context and status: #10688.