chore(template): sync with dailydevops/dotnet-template [skip ci]

Author: samtrion

.github/instructions/blazor.instructions.md

@@ -13,7 +13,7 @@ description: 'This file contains instructions for Blazor development.
 * MUST write idiomatic and efficient Blazor and C# code.
 * MUST follow .NET and Blazor conventions and best practices.
 * MUST use Razor Components appropriately for component-based UI development.
-* MUST use the latest version C#, currently C# 13 features like record types, pattern matching, and global usings.
+* MUST use the latest version C#, currently C# 13 features like record types, pattern matching, and global usings (see [.NET 10 and C# 13 Adoption](../../decisions/2025-07-11-dotnet-10-csharp-13-adoption.md)).
 * MUST use async/await where applicable to ensure non-blocking UI operations.
 
 ## Code Style and Structure

.github/instructions/csharp.instructions.md

@@ -21,8 +21,26 @@ description: 'This file contains instructions for C# development.
 Follow these C# coding conventions for consistency across the project.
 
 * MUST use `var` when the type is obvious from the right side of the assignment.
-* MUST use `Argument.ThrowIfNull(x)` instead of `if (x == null) throw new ArgumentNullException(nameof(x))`, when nuget package `NetEvolve.Arguments` is referenced.
-* MUST use `ArgumentNullException.ThrowIfNull(x)` instead of `if (x == null) throw new ArgumentNullException(nameof(x))`, when nuget package `NetEvolve.Arguments` is not referenced.
+* MUST use appropriate null-checking pattern based on package availability:
+  - When `NetEvolve.Arguments` package is referenced in project: Use `Argument.ThrowIfNull(x)`
+  - When `NetEvolve.Arguments` package is NOT referenced: Use `ArgumentNullException.ThrowIfNull(x)`
+  - Check `Directory.Packages.props` for `NetEvolve.Arguments` availability
+  - Example with NetEvolve.Arguments:
+    ```csharp
+    public void ProcessData(string data)
+    {
+        Argument.ThrowIfNull(data);
+        // process data
+    }
+    ```
+  - Example without NetEvolve.Arguments:
+    ```csharp
+    public void ProcessData(string data)
+    {
+        ArgumentNullException.ThrowIfNull(data);
+        // process data
+    }
+    ```
 
 ## Formatting
 

.github/instructions/decisions.instructions.md

@@ -132,7 +132,8 @@ If decisions appear to conflict:
 1. **Check states**: "accepted" decisions override "proposed" ones
 2. **Check dates**: More recent decisions (`lastModified`) take precedence
 3. **Check specificity**: More specific `applyTo` patterns override generic ones
-4. **Ask user**: If conflict remains unclear, request user clarification
+4. **Decisions vs. Instructions**: Accepted decisions from `decisions/` folder override technical instructions from `.github/instructions/` when both apply to the same situation
+5. **Ask user**: If conflict remains unclear, request user clarification
 
 ## Decision Updates
 

AGENTS.md

@@ -38,7 +38,10 @@ These files control project-wide settings and should remain unchanged unless spe
 * MUST NEVER change `global.json` unless explicitly asked to.
 * MUST NEVER change `Directory.Build.props` unless explicitly asked to.
 * MUST NEVER change `Directory.Build.targets` unless explicitly asked to.
-* MUST NEVER change `Directory.Packages.props` unless explicitly asked to.
+* MUST NEVER change `Directory.Packages.props` structure or properties unless explicitly asked to.
+  - MAY add new `<PackageVersion>` entries for required NuGet packages.
+  - MUST NOT modify existing package versions without explicit user request.
+  - MUST NOT change MSBuild properties like `ManagePackageVersionsCentrally`.
 
 ## Code Reviews and Implementation