[WIP] Add device history tracking for wake/sleep events

[Claude]

Thanks for asking me to work on this. I will get started on it and keep this PR's description up to date as I form a plan and make progress.

---

This section details on the original issue you should resolve

<issue_title>Feature: Device History — Track wake/sleep events with timestamps</issue_title>
<issue_description>## Description

Record and display a history of device events: wake commands sent, device came online, device went offline. This provides visibility into device behavior and supports future analytics (v2.0.0).

Affected Files

• New model: src/API/Models/DeviceEvent.cs — Id, PcDeviceId (FK), EventType (enum: WakeCommandSent, CameOnline, WentOffline), Timestamp, Details (optional string, e.g., ping latency)
• src/API/Data/AppDbContext.cs — DbSet<DeviceEvent>, migration, index on (PcDeviceId, Timestamp)
• src/API/Services/DeviceMonitoringService.cs — Log CameOnline / WentOffline events when status changes (currently only updates IsOnline and OnlineSince)
• src/API/Handler/PcDeviceHandler.cs — Log WakeCommandSent event in WakeDevice()
• New endpoints (in existing or new strategy):
  • GET /api/v1/pc-devices/{id}/history?limit=50&offset=0 — paginated event history
  • Optional: GET /api/v1/pc-devices/{id}/history/summary — uptime stats
• New UI component: Device history dialog or expandable section showing event timeline
• src/UI/Pages/Home.razor — "History" action button on each device

Design Decisions

1. Retention policy: Events will grow indefinitely. Add a configurable max-age or max-count with automatic cleanup (e.g., keep last 90 days or 1000 events per device).
2. Scoped DB context: DeviceMonitoringService is a singleton but AppDbContext is scoped — use IServiceScopeFactory (already the pattern used in DeviceMonitoringService.CheckAllDevicesAsync).
3. Event granularity: Log every check cycle vs. only status changes. Recommend only status changes + explicit wake commands to keep volume manageable.

Acceptance Criteria

• A DeviceEvent is recorded each time a wake command is sent
• A DeviceEvent is recorded when a device transitions online → offline or offline → online
• Events are viewable per device in the UI with timestamps
• API supports paginated history retrieval
• Events are stored in SQLite and survive restarts
• Deleting a device cascades to its event history
• Unit tests cover event recording in monitoring service and handler
  </issue_description>

Comments on the Issue (you are @claude[agent] in this section)

[renedierking]

@claude[agent] where is the UI Component

[Claude]

@claude[agent] where is the UI Component

I've added the UI component in commit f0cb463. The implementation includes:

DeviceHistoryDialog Component:

• Timeline view showing all device events (Wake Command Sent, Came Online, Went Offline)
• Color-coded icons and text (blue for wake commands, green for online, red for offline)
• Human-readable timestamps ("5m ago", "2h ago", or full date for older events)
• Paginated loading with "Load More" button (20 events per page)
• Displays event details when available

Integration:

• Added History icon button to DeviceCard (visible in card view)
• Added History icon button to table view actions column
• Clicking the History button opens a modal dialog showing the device's event timeline

The UI component uses MudBlazor's MudTimeline for the visual timeline and connects to the device history API endpoint (GET /api/v1/pc-devices/{id}/history) that was implemented in the previous commit.

[renedierking]

good