[AIDE-122] Usage Updates

[chandlerhuff]

Summary

Enhances the usage dashboard with spend records and a configurable usage end date. The page now shows "Spend records" tiles with the highest 7-day and 30-day spend windows across all retained usage, and a calendar date picker that lets users bound the rolling ranges to a specific end date instead of always ending today.

Changes

• Added spendPeaks GraphQL field returning the highest rolling 7-day and 30-day spend windows (CcusageSpendWindow/CcusageSpendPeaks), computed across all retained dates while honoring history, agent, and model filters.
• Added an optional endDate argument to the aggregate query field so bounded ranges (7/30 days) use a specific inclusive end date instead of today; ignored for ALL and validated as strict YYYY-MM-DD.
• Added a calendar end-date picker to the usage page (shown only for bounded ranges) that disables future dates and refetches usage for the selected end date.
• Changed the default range from ALL to LAST_30_DAYS so spend records are visible by default.
• Spend records refresh when the active agent or model filter changes, without triggering a new data collection.
• Added aggregation utilities (highestUsageSpendWindow, usageSpendPeaks, filterUsageByModel, usagePeriodForDate, usagePeriodToDate) and extended filterUsageByDays with an upper date bound; peaks tie-break to the latest window.
• Localized new strings in English, German, Spanish, and French, including accessible labels for the spend record tiles and date picker.
• Added unit and component tests covering end-date filtering, date validation, spend-window calculation, and resolver wiring.

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Ticket: AIDE-122