feat(dashboard): expose additional drive metrics — available space, self-test history, performance

[Starosdev]

Feature Request

Environment

• Affected: Both
• Component: Backend / Frontend

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Description

Umbrella issue tracking expansion of drive metrics surfaced in the dashboard and device detail view. Three metric categories are currently missing from the UI despite partial backend support:

1. Available Space

Drive capacity and free space are not shown anywhere in the UI. smartctl reports capacity; filesystem free space could be read from the host. Useful for monitoring drives approaching full.

2. Self-Test History

smartctl returns ata_smart_self_test_log with pass/fail history for short and extended self-tests. This data is parsed in collector/smart.go but not persisted or displayed. Showing recent self-test results on the device detail page would give users direct visibility into drive health checks.

3. Drive Performance Summary

Performance benchmark data (fio results) is collected by the performance collector and stored via /api/device/:wwn/performance, but there is no UI to browse or trend this data on the device detail page.

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Technical Details

• Self-test log parsed: webapp/backend/pkg/models/collector/smart.go:168
• Performance API endpoint: GET /api/device/:wwn/performance
• Available space: no current collection — needs new collector logic or OS-level query

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Acceptance Criteria

• Self-test history displayed on device detail page (pass/fail, date, type)
• Performance benchmark history viewable on device detail page
• Available space shown on device card and detail page (capacity + used + free)
• All three metrics included in device detail API response
• Mobile card layout updated to include new metrics

[Starosdev]

Status audit: current develop displays ATA self-test history and performance benchmarks on the detail page, and has a filesystem capacity panel with available, used, and total bytes. Remaining gap: per-drive available/free space on device cards and detail, plus any required API/mobile parity. Keeping open for residual scope.