[manuelmayer-dev]

Closes #1295

Summary

The AdGuard Home, Jellyfin, Twitch, YouTube, Steam and Weather details widgets now live in their integrations and reach the host only through the Plugin SDK, so each integration could become an out-of-process plugin. The SDK gains what they needed, additively and for plugins too, and Music Player album colours became a system integration.

Testing

Full solution build and test suites pass (only the Plugin CLI build test fails on this Mac because of the pinned SDK). On a disposable host the moved widgets render with their icons and presses are refused while the computer is locked; Twitch and YouTube were not run live (they need an account).

Plugin SDK / API compatibility

• No public, non-obsolete SDK or plugin protocol contract was removed or changed
• Contracts were only extended additively (new members with defaults, new optional fields, new message types)
• Anything being retired carries [Obsolete] and [MacroDeckDeprecated], is in the deprecation registry, and still works
• A plugin compiled against the previous SDK still loads and behaves identically (source and binary compatible)
• The conformance suite passes and the sample plugin builds and runs unchanged
• Any intentional break was explicitly agreed beforehand and is described below

Notes

Agreed behaviour changes, listed in the compatibility policy: plugin widget events are refused while the host is locked, and a weather plugin built against an older SDK declares no details action, so its stations get no default press. The UI resource quota rises to 1024 resources and 48 MiB per plugin. The conformance suite passes; the sample plugin was not run.

Checklist

• Tests were added or updated where needed
• The change was verified manually where appropriate
• Documentation was updated if the change affects documented behaviour
• I reviewed and understand every submitted change