dashboard: Acquisition view surfaces per-repo synchronized history #161

Part of #157.

Surface the synchronized history in the CSSC Dashboard Acquisition view.

Scope (apps/python-app/services/dashboard-web)

• Consume the packages-service history endpoint (dashboard: packages-service reads the mirror-history artifact (+ endpoint) #160) in the AcquisitionProvider / BFF.
• Each Acquisition card shows a Synchronized list alongside its promotion issues: source tag/digest already mirrored, with syncedAt timestamp and a run link.
• Fix the in_quarantine signal: exclude the reserved mirror-history tag so a history-only package (image already promoted and deleted) is not shown as if an image were still awaiting promotion.
• Template/htmx rendering + tests.

Depends on: #160.
Design: docs/architecture/acquire/mirror-history.md (Dashboard integration).