Upgrade project to the Avalonia 12 baseline and Plugin SDK v5: centralize Avalonia packages, remove legacy WebView.Avalonia usage (use NativeWebView/WebView2 EnvironmentRequested), and update Fluent/Material icon/package usages. Bump multiple package/project versions to 5.0.0 and Avalonia 12.0.1, update plugin template and README/docs to SDK v5, and add PLUGIN_SDK_V5_MIGRATION.md.
Also fix runtime/behavior bugs: make DataLocationResolver use a fixed bootstrap launcher data path and avoid recursive ResolveDataRoot; add legacy-state handling and extraction in OobeStateService; and update component settings tests to reflect migrated storage (DB/backup) and reset cache for test reloads. Various csproj, tests, and docs updated to reflect the migration and ensure build/test compatibility.
Add automatic release version stamping and multiple launcher reliability improvements. The Release workflow now runs scripts/Set-ReleaseVersion.ps1 in build jobs to inject tag-derived Version/AssemblyVersion into project metadata; several .csproj/Directory.Build.props and app.manifest files were changed to use a dev placeholder. Introduced AppVersionProvider (and related runtime metadata) to centralize version resolution and updated DeploymentLocator to use it and to prefer package-root/version.json. Launcher startup flow was hardened: added startup success tracking, public-activation recovery path, improved success/fallback semantics, and related IPC handling. UI/UX fixes include OOBE entrance/exit animation improvements (scaling-aware, concurrent fade+translate) and minor window lifecycle reorder in DesktopShellHost. CommandContext now recognizes restart and key=value args. New DesktopTrayService and .trae spec files (spec, checklist, tasks) document shell/tray hardening work. Miscellaneous logging, comments and housekeeping edits across launcher and shared contracts to support the above.
