christian289

WPF IValueConverter rules: MarkupExtension singleton, pure functions, null/UnsetValue handling, TemplateBinding.

WPF Freezable performance rules: Freeze() all Brush/Pen/Geometry; create-and-freeze in constructor, reuse in OnRender.

WPF MVVM layer-separation rules: no System.Windows in ViewModels, BCL-only types, CommunityToolkit.Mvvm base classes. Preloaded into MVVM-related wpf-dev-pack agents.

Banned wpf-dev-pack patterns (P-001..P-004): ViewModelLocator, code-behind DataContext, Stateless ViewModel, mixing composition paths.

WPF rendering anti-patterns: no InvalidateVisual in loops, no resource allocation in OnRender.

WPF ResourceDictionary rules: Generic.xaml as MergedDictionaries hub only, per-control style files, resource order.

View-ViewModel wiring for CommunityToolkit.Mvvm: Mappings.xaml + implicit DataTemplate (ViewModel First).

View-ViewModel wiring for Prism 9: RegisterForNavigation + IRegionManager (View First).

Force Regex to use GeneratedRegex Source Generator attribute instead of runtime Regex construction for compile-time optimization.

Force all DTO (Data Transfer Object) types to be declared as record instead of class for immutability and value-based equality.

Force record instantiation via positional constructor with named arguments instead of property initializer syntax for stronger immutability expression.

Enforce branch-based workflow with meaningful Korean commits and PR creation for traceable decision history.

Force JsonSerializerOptions to be declared as static readonly or readonly fields instead of creating new instances inside methods.

Centralize external namespace imports (BCL, FCL, NuGet) in a GlobalUsings.cs file per project, keeping individual files clean.

Renders MewUI custom elements using absolute Bounds coordinates. Use when alignment appears ignored or element renders at top-left.

Streams raw video frames via ffmpeg stdout pipe. Use for real-time video processing without preprocessing.

Diagnose and fix Windows Remote Desktop (RDP) login or connection failures, especially over Tailscale/VPN and especially for PCs signed in with a Microsoft account. Use this WHENEVER the user reports RDP trouble on Windows — "RDP 로그인이 안 돼요" / "remote desktop credentials rejected" / "자격 증명이 작동하지 않습니다" / "can't connect to my PC over Tailscale" / "Windows Hello only sign-in blocks remote login" / PIN-vs-password confusion / NLA failures / "remote desktop keeps disconnecting after a few seconds". Covers the read-only diagnostic sweep (RDP enabled, TermService, port 3389, firewall incl. localized rule names, NLA, account type/admin/lockout, Tailscale), the crucial "can't connect vs credentials rejected" fork, Microsoft-account gotchas (DevicePasswordLessBuildVersion / Windows-Hello-only toggle needing a reboot, username format, passwordless accounts, stale cached password), event-log forensics, and account-lockout confounders. Trigger even if the user doesn't say the word "RDP" but clearly can't remote into a Wind