chore: solution review & modernization — AI config, CI coverage, test coverage

[Copilot]

Broad modernization pass: updates Copilot AI configuration to reflect current patterns, wires up code coverage in CI, and adds test coverage for previously untested public members.

AI / Copilot system

• copilot-instructions.md — adds SharedCode.Data.Tests to the module table; adds a C# 13 / .NET 10 Modern Features section covering collection expressions, params ReadOnlySpan<T>, primary constructors, field keyword, allows ref struct; expands testing conventions for both test projects
• create-module.prompt.md — target frameworks template now includes net8.0
• add-test-class.prompt.md (new) — MSTest scaffolding guide with single-scenario, [DataRow], and Assert.ThrowsExactly exception templates
• improve-coverage.prompt.md (new) — coverage-gap identification guide with per-member checklist and known gap table
• maintain-copilot-instructions.yml — also validates required prompt files exist; opens an issue if any are missing
• .vscode/mcp.json — switches GitHub MCP from Docker to npx; adds sequential-thinking and dotnet-skills servers

Build / CI

• dotnet.yml — adds --collect:"XPlat Code Coverage" + Cobertura artifact upload
• Directory.Build.props — re-enables the SourceRevisionId <Output> element that was commented out, preventing source revision from ever being set; IgnoreExitCode=True for git-less builds
• Directory.Packages.props — AwesomeAssertions 9.1.0 → 9.2.0

editorconfig

• Both test project .editorconfig files: CA1515 suppressed at project level (MSTest requires public test classes, making per-class [SuppressMessage] boilerplate unnecessary)

Test coverage (+38 methods across 6 new files)

File	Members covered
AssemblyExtensionsTests	GetAttribute<T> — found, not found, null guard
EventHandlerExtensionsTests	All Raise overloads — null handler, value-wrapped, EventArgs
ExtensionsTests	IsBetween, In, IfNotNull, IsNull, IsNotNull, ChangeType<T>, GetPropertyValue<T>
FunctionExtensionsTests	Memoize — cache miss, hit, multiple keys, null guard
PropertySupportTests	ExtractPropertyName — valid expression, null expression
TypeExtensionsTests	GetDisplayName, IsNullable, IsBoolean, IsString, BaseType, IsSubclassOfTypeByName

[Copilot]

Pull request overview

Modernization pass across the SharedCode .NET solution to (1) keep Copilot prompt/config documentation aligned with current practices, (2) improve CI observability via code coverage collection, and (3) expand unit-test coverage for core utilities.

Changes:

• Added/updated Copilot prompt + instruction docs and workflow validation for required prompt files.
• Updated CI and build props to capture coverage artifacts and re-enable SourceRevisionId population.
• Added new MSTest coverage for several previously untested SharedCode.Core public members and adjusted test-project analyzer settings.

Reviewed changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
SharedCode.Data.Tests/.editorconfig	Suppresses CA1515 at the test-project level.
SharedCode.Core.Tests/.editorconfig	Suppresses CA1515 at the test-project level.
SharedCode.Core.Tests/AssemblyExtensionsTests.cs	Adds unit tests for AssemblyExtensions.GetAttribute<T>().
SharedCode.Core.Tests/EventHandlerExtensionsTests.cs	Adds unit tests for EventHandlerExtensions.Raise(...) overloads.
SharedCode.Core.Tests/ExtensionsTests.cs	Adds unit tests for various Extensions helpers (e.g., IsBetween, In, ChangeType, GetPropertyValue).
SharedCode.Core.Tests/FunctionExtensionsTests.cs	Adds unit tests for FunctionExtensions.Memoize(...).
SharedCode.Core.Tests/PropertySupportTests.cs	Adds unit tests for PropertySupport.ExtractPropertyName<T>().
SharedCode.Core.Tests/TypeExtensionsTests.cs	Adds unit tests for TypeExtensions helpers (e.g., GetDisplayName, IsNullable).
Directory.Packages.props	Updates AwesomeAssertions and analyzer package versions.
Directory.Build.props	Re-enables SourceRevisionId capture and allows git-less builds via IgnoreExitCode=True.
.vscode/mcp.json	Switches GitHub MCP server to npx and adds additional MCP servers.
.github/workflows/maintain-copilot-instructions.yml	Extends validation to include required .github/prompts/* files and updates issue wording.
.github/workflows/dotnet.yml	Collects XPlat code coverage during tests and uploads Cobertura reports as an artifact.
.github/prompts/maintain-copilot-instructions.prompt.md	Updates maintenance checklist to include new/updated prompts and MCP guidance.
.github/prompts/improve-coverage.prompt.md	New prompt describing a process for identifying and filling coverage gaps.
.github/prompts/create-module.prompt.md	Updates module scaffolding template to include net8.0 target.
.github/prompts/add-test-class.prompt.md	New prompt for MSTest scaffolding; contains a couple template issues noted in review comments.
.github/copilot-instructions.md	Updates module table and adds a C# 13/.NET 10 features section; expands testing conventions.

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[Copilot]

Pull request overview

Copilot reviewed 18 out of 18 changed files in this pull request and generated no new comments.

Suppressed comments (3)

SharedCode.Core.Tests/ExtensionsTests.cs:35

• This parameterized test uses [DataRow] but is marked [TestMethod]. To match the new testing guidance added in this PR (use [DataTestMethod] for [DataRow] tests), switch this to [DataTestMethod].

    [TestMethod]
    [DataRow(0, 1, 10)]
    [DataRow(11, 1, 10)]
    public void IsBetween_ValueOutOfRange_ReturnsFalse(int value, int low, int high)

SharedCode.Core.Tests/ExtensionsTests.cs:15

• These tests are parameterized with [DataRow], but the attribute is [TestMethod]. In this PR you added add-test-class.prompt.md which instructs using [DataTestMethod] + [DataRow] for parameterized tests, so this new test should follow that convention.

This issue also appears on line 32 of the same file.

    [TestMethod]
    [DataRow(5, 1, 10)]
    [DataRow(1, 1, 10)]
    [DataRow(10, 1, 10)]
    public void IsBetween_ValueInRange_ReturnsTrue(int value, int low, int high)

.github/copilot-instructions.md:169

• Testing docs currently say assertions are done with AwesomeAssertions, but the new add-test-class.prompt.md and the new tests added in this PR use MSTest Assert.*. This inconsistency will lead to mixed guidance for contributors; please align the instructions to reflect the intended assertion style (or explicitly document that both are acceptable).

- **Framework**: MSTest (`[TestClass]`, `[TestMethod]`, `[DataRow]`, `[DataTestMethod]`)
- **Assertions**: AwesomeAssertions
- **Pattern**: Arrange / Act / Assert with blank lines separating each block