Add AGENTS.md with comprehensive build and test documentation

[Copilot]

Description

Resurrects documentation from closed PR #1571. Adds AGENTS.md to repository root with comprehensive build and test instructions for developers and CI/CD agents.

AGENTS.md Contents

General Guidelines

• Code review: only make high confidence suggestions when reviewing code changes
• Always use the latest stable version of C#
• Never add or change global.json unless explicitly asked to
• Never change NuGet.config files unless explicitly asked to
• Null handling: declare variables non-nullable, check for null at public API entry points; for internal code, trust C# null annotations
• Testing: do not emit "Act", "Arrange" or "Assert" comments in test code

Prerequisites and Build

• Prerequisites: .NET SDK 10.0 and .NET Runtimes for 8.0 and 9.0
• Quick start: simple dotnet build and dotnet test commands for quick iteration; full solution build in Release mode for final validation
• Testing requirements: code coverage should be maintained or increased
• Points to .github/workflows/Steeltoe.All.yml for detailed test procedures including environment-specific filters and test categories
• Integration tests require Docker containers (Config Server, Eureka Server) to be running
• Platform-specific test skipping uses attributes like [FactSkippedOnPlatform] and [TheorySkippedOnPlatform] instead of trait categories
• Code style validation instructions (using cleanupcode.ps1 and .github/workflows/verify-code-style.yml)

Troubleshooting

• Troubleshooting guide including build warnings during refactoring (/p:TreatWarningsAsErrors=false)
• Important note that all warnings should be addressed before committing final changes
• Note clarifying that Steeltoe Azure Container Registry allows anonymous pulls (no authentication required)

Based on .github/workflows/Steeltoe.All.yml workflow commands.

Code Changes

• ManagementOptionsTest.cs - Renamed DefaultJsonSerializerOptions to ExpectedJsonSerializerOptions to better reflect that these are the expected serializer settings that tests assert against, not the default system settings

The JavaScriptEncoder remains configured with UnsafeRelaxedJsonEscaping in ConfigureManagementOptions.cs as originally designed, which is required for the route mappings actuator to make generic method signatures human-readable (e.g., backticks in generic type names).

Branch Updates

Merged latest changes from main branch, including updates to test attributes that replace [Trait("Category", "SkipOnMacOS")] with [FactSkippedOnPlatform(nameof(OSPlatform.OSX))].

Fixes #1571

Quality checklist

• Your code complies with our Coding Style.
• You've updated unit and/or integration tests for your change, where applicable.
• You've updated documentation for your change, where applicable.
  If your change affects other repositories, such as Documentation, Samples and/or MainSite, add linked PRs here.
• There's an open issue for the PR that you are making. If you'd like to propose a new feature or change, please open an issue to discuss the change or find an existing issue.
• You've added required license files and/or file headers (explaining where the code came from with proper attribution), where code is copied from StackOverflow, a blog, or OSS.

Original prompt

Let's resurrect some pieces of PR #1571, namely adding agents.md and the JavaScriptEncoder related changes

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[TimHess]

@copilot review the commit history in #1571 to see the JavaScriptEncoder changes from .UnsafeRelaxedJsonEscaping to .Create(UnicodeRanges.BasicLatin, UnicodeRanges.Latin1Supplement) and back again -- re-implement the change.

Also, the Steeltoe Azure Container Registry allows anonymous pulls and no agent will have credentials that work with it. Update Agents.md accordingly

[Copilot]

@copilot review the commit history in #1571 to see the JavaScriptEncoder changes from .UnsafeRelaxedJsonEscaping to .Create(UnicodeRanges.BasicLatin, UnicodeRanges.Latin1Supplement) and back again...

Done. Changed JavaScriptEncoder from UnsafeRelaxedJsonEscaping to Create(UnicodeRanges.BasicLatin, UnicodeRanges.Latin1Supplement) in ConfigureManagementOptions.cs, DebugSerializerOptions.cs, and FluentAssertionsExtensions.cs. Also updated AGENTS.md to clarify that the Steeltoe Azure Container Registry allows anonymous pulls. (commit b37bdce)

[github-actions]

Summary - All Code Coverage (ubuntu-latest)

Assembly	Line coverage	Branch coverage
Steeltoe.Bootstrap.AutoConfiguration	97.4%	100%
Steeltoe.Common	85.6%	80.6%
Steeltoe.Common.Certificates	96.2%	85.5%
Steeltoe.Common.Hosting	84%	70%
Steeltoe.Common.Http	100%	85.2%
Steeltoe.Common.Logging	81.1%	56.2%
Steeltoe.Common.Net	64.5%	66.6%
Steeltoe.Configuration.Abstractions	98.5%	91.1%
Steeltoe.Configuration.CloudFoundry	99.1%	91.8%
Steeltoe.Configuration.ConfigServer	97.2%	91.6%
Steeltoe.Configuration.Encryption	97.6%	92.4%
Steeltoe.Configuration.Kubernetes.ServiceBindings	95.1%	89.3%
Steeltoe.Configuration.Placeholder	93.8%	84.7%
Steeltoe.Configuration.RandomValue	93.2%	90%
Steeltoe.Configuration.SpringBoot	98.3%	95%
Steeltoe.Connectors	93.9%	89.8%
Steeltoe.Connectors.EntityFrameworkCore	81.5%	75%
Steeltoe.Discovery.Configuration	92.3%	100%
Steeltoe.Discovery.Consul	98.1%	94.8%
Steeltoe.Discovery.Eureka	91.8%	85.2%
Steeltoe.Discovery.HttpClients	94.2%	95.4%
Steeltoe.Logging.Abstractions	99.4%	96.9%
Steeltoe.Logging.DynamicConsole	100%	95.4%
Steeltoe.Logging.DynamicSerilog	99.1%	95.4%
Steeltoe.Management.Abstractions	100%	100%
Steeltoe.Management.Endpoint	95.5%	89.1%
Steeltoe.Management.Prometheus	95.9%	91.6%
Steeltoe.Management.Tasks	100%	****
Steeltoe.Management.Tracing	100%	75%
Steeltoe.Security.Authentication.JwtBearer	100%	100%
Steeltoe.Security.Authentication.OpenIdConnect	73.8%	59%
Steeltoe.Security.Authorization.Certificate	96.3%	75%
Steeltoe.Security.DataProtection.Redis	100%	****

[TimHess]

@copilot add some more content for agents.md

In general:
Only make high confidence suggestions when reviewing code changes.
Always use the latest version C#, currently C# 13 features.
Never add or change global.json unless explicitly asked to.
Never change NuGet.config files unless explicitly asked to.
Declare variables non-nullable, and check for null at entry points.
Trust the C# null annotations and don't add null checks when the type system says a value cannot be null.

For build troubleshooting:
If temporarily introducing warnings during refactoring, add /p:TreatWarningsAsErrors=false to prevent build failure
Important: All warnings should be addressed before committing any final changes

When writing tests:
Do not emit "Act", "Arrange" or "Assert" comments.

[Copilot]

@copilot add some more content for agents.md

In general:
...

Added the requested content to AGENTS.md including:

• General Guidelines section with code review, C# 13 features, and config file restrictions
• Null handling guidelines (non-nullable variables, trust null annotations)
• Testing guidelines (no Act/Arrange/Assert comments)
• Build troubleshooting for /p:TreatWarningsAsErrors=false during refactoring with reminder to fix warnings before commit

(commit fb6b63a)

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud