Add stdin-path test coverage for stdio server auth validation

[Copilot]

Review comment noted missing test coverage for the validateServerAuth path when a stdio server includes an auth block via the stdin JSON config path, leaving the structured error type and message unguarded against regressions.

Changes

• TestConvertStdinServerConfig_ValidationError — added "stdio with auth block" table case to cover the error message via convertStdinServerConfig (the stdin JSON path)
• TestConvertStdinServerConfig_StdioWithAuth — focused test asserting the returned error is a *rules.ValidationError with the correct Field, Message, JSONPath, and non-empty Suggestion:

var valErr *rules.ValidationError
require.True(t, errors.As(err, &valErr))
assert.Equal(t, "auth", valErr.Field)
assert.Contains(t, valErr.Message, "auth is only supported for HTTP servers")
assert.Contains(t, valErr.JSONPath, "mcpServers.my-server")
assert.NotEmpty(t, valErr.Suggestion)

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• example.com
  • Triggering command: /tmp/go-build2349467698/b514/launcher.test /tmp/go-build2349467698/b514/launcher.test -test.testlogfile=/tmp/go-build2349467698/b514/testlog.txt -test.paniconexit0 -test.timeout=10m0s go_.�� @v1.43.0/semconv-errorsas @v1.43.0/semconv-ifaceassert x_amd64/vet . --gdwarf2 --64 LEXxvrp/NoLlItYx-buildtags -I g_.a -I x_amd64/vet --gdwarf-5 --64 -o x_amd64/vet (dns block)
• invalid-host-that-does-not-exist-12345.com
  • Triggering command: /tmp/go-build2349467698/b496/config.test /tmp/go-build2349467698/b496/config.test -test.testlogfile=/tmp/go-build2349467698/b496/testlog.txt -test.paniconexit0 -test.timeout=10m0s /tmp/go-build2349467698/b392/vet.cfg g_.a k/gh-aw-mcpg/gh-aw-mcpg/internal-nolocalimports x_amd64/vet -dynout xcontext -dynlinker x_amd64/vet (dns block)
• nonexistent.local
  • Triggering command: /tmp/go-build2349467698/b514/launcher.test /tmp/go-build2349467698/b514/launcher.test -test.testlogfile=/tmp/go-build2349467698/b514/testlog.txt -test.paniconexit0 -test.timeout=10m0s go_.�� @v1.43.0/semconv-errorsas @v1.43.0/semconv-ifaceassert x_amd64/vet . --gdwarf2 --64 LEXxvrp/NoLlItYx-buildtags -I g_.a -I x_amd64/vet --gdwarf-5 --64 -o x_amd64/vet (dns block)
• slow.example.com
  • Triggering command: /tmp/go-build2349467698/b514/launcher.test /tmp/go-build2349467698/b514/launcher.test -test.testlogfile=/tmp/go-build2349467698/b514/testlog.txt -test.paniconexit0 -test.timeout=10m0s go_.�� @v1.43.0/semconv-errorsas @v1.43.0/semconv-ifaceassert x_amd64/vet . --gdwarf2 --64 LEXxvrp/NoLlItYx-buildtags -I g_.a -I x_amd64/vet --gdwarf-5 --64 -o x_amd64/vet (dns block)
• this-host-does-not-exist-12345.com
  • Triggering command: /tmp/go-build2349467698/b523/mcp.test /tmp/go-build2349467698/b523/mcp.test -test.testlogfile=/tmp/go-build2349467698/b523/testlog.txt -test.paniconexit0 -test.timeout=10m0s -o g_.a -trimpath x_amd64/vet -p ernal/server -lang=go1.25 x_amd64/vet ut-1�� .cfg -buildtags x_amd64/vet ctor -ifaceassert E=3 x_amd64/vet (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
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[Copilot]

Pull request overview

This PR adds test coverage for the stdin JSON config conversion/validation path to ensure that stdio servers configured with an auth block fail with a stable, structured rules.ValidationError (including message, JSONPath, and suggestion), preventing regressions in error typing/formatting.

Changes:

• Extends TestConvertStdinServerConfig_ValidationError with a "stdio with auth block" table case to cover the stdin conversion validation message.
• Adds TestConvertStdinServerConfig_StdioWithAuth to assert the returned error is a *rules.ValidationError with expected Field, Message, JSONPath, and non-empty Suggestion.

Show a summary per file

File	Description
internal/config/config_stdin_test.go	Adds stdin-path tests asserting stdio+auth is rejected and that the structured validation error remains stable.

Copilot's findings

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• Files reviewed: 1/1 changed files
• Comments generated: 1

[Copilot]

TestConvertStdinServerConfig_StdioWithAuth says it verifies the “correct JSONPath”, but the assertion uses assert.Contains on valErr.JSONPath. Since the expected path is deterministic (mcpServers.my-server), asserting equality would make this test stricter and better at catching regressions (e.g., a different prefix/suffix that still contains the substring).

Suggested change

	assert.Contains(t, valErr.JSONPath, "mcpServers.my-server")
	assert.Equal(t, "mcpServers.my-server", valErr.JSONPath)