UX: restructure project status card for at-a-glance state

[Unthred]

Summary

Restructure the hover/status-panel project card into a compact labelled status grid so BUILD / AGENT / CHANGES / LAST BUILD can be scanned at a glance.

Why

PR #57/#58 exposes richer control-plane state on project cards. The information is useful but currently rendered as sequential prose with duplicated warnings counts, making cards hard to scan.

Acceptance

• Structured rows (BUILD, AGENT, CHANGES, LAST BUILD) via presentation model (not ad-hoc WPF strings)
• No duplicate semantic information (warnings/errors, agent busy headline)
• Dynamic rows — omit irrelevant state
• Keep traffic-light rail and action buttons
• Presentation tests for healthy / warnings / failed / building / busy / queued / idle / debounce / rebuild / ship-check
• Linked to Enhancement: show agent control-plane state in project status #57 / PR #57: Show agent control-plane state on project status cards #58

Closes when merged with or immediately after #58.

[Unthred]

Implements UX refinement for status cards exposed by #57 / #58