Add Mockly Copilot skill and auto-copy to .agents/skills

[dennisdoomen]

Summary

Adds a Copilot skill (SKILL.md) to the Mockly NuGet package, following the same pattern as StructId.

What's included

SKILL.md — A comprehensive AI skill guide for Mockly, derived from all unit tests under Mockly.Specs and FluentAssertions.Mockly. Covers:

• Basic setup and HttpMock configuration
• HTTP method mocking (GET, POST, PUT, PATCH, DELETE)
• URL matching: path, query, scheme, host, wildcards, URL shortcut overloads
• Request body matching: wildcard, JSON equivalence, regex, custom predicates (sync/async)
• Response configuration: status code, JSON, raw content, OData v4 envelope, HttpContent, custom lambda
• IResponseBuilder<T> integration for test-data builders
• Request capture — global mock.Requests and scoped RequestCollection
• Invocation limits: Once(), Twice(), Times(n)
• Fluent continuation building and Reset() / Clear()
• IHttpClientFactory support
• FluentAssertions.Mockly assertions (HaveAllRequestsCalled, NotContainUnexpectedCalls, BeExpected, etc.)

Mockly/Mockly.targets — MSBuild CopyMocklySkill target that runs BeforeTargets="PrepareForBuild". It resolves the consuming project's repo root (via git SourceRoot → $(SolutionDir) → nearest AGENTS.md) and copies SKILL.md to .agents/skills/mockly/SKILL.md. Uses SkipUnchangedFiles="true" and ContinueOnError="true" so it never breaks builds.

Mockly/Mockly.csproj — Two new <None> pack items:

• SKILL.md → skills/mockly/SKILL.md (inside the package)
• Mockly.targets → buildTransitive/Mockly.targets (auto-imported by consumers)

Opt-out

Consumers can disable the skill copy by adding to their project or Directory.Build.props:

<PropertyGroup>
  <MocklySkill>false</MocklySkill>
</PropertyGroup>

[github-actions]

Test Results

  3 files  ±0    3 suites  ±0   6s ⏱️ -7s
 89 tests ±0   89 ✅ ±0  0 💤 ±0  0 ❌ ±0 
175 runs  ±0  175 ✅ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit 2e514d2. ± Comparison against base commit 60348c0.

♻️ This comment has been updated with latest results.

[coveralls]

Coverage Report for CI Build 26331555331

Coverage remained the same at 83.649%

Details

• Coverage remained the same as the base build.
• Patch coverage: No coverable lines changed in this PR.
• No coverage regressions found.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

No coverage regressions found.

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Coverage Stats

Relevant Lines:	1010
Covered Lines:	899
Line Coverage:	89.01%
Relevant Branches:	311
Covered Branches:	206
Branch Coverage:	66.24%
Branches in Coverage %:	Yes
Coverage Strength:	334.8 hits per line

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💛 - Coveralls