Clarify npm and pip package name validation errors

[Copilot]

✨ Enhancement

Invalid npm/pip package names currently fail with value-only errors, which force workflow authors to look up naming rules elsewhere. This updates those validation errors to explain the constraint inline and show a canonical valid example.

• What does this improve?

  • npm and pip package-name validation errors now include the rule summary and a concrete example, not just the rejected value.
  • Existing validator tests now assert the user-facing guidance, so future changes preserve the improved error quality.

• Why is this valuable?

  • Shortens time-to-fix for common workflow authoring mistakes.
  • Brings these validation errors closer to the more actionable patterns already used elsewhere in the codebase.

• Implementation approach:

  • Updated pkg/workflow/name_validation.go to expand the npm and PyPI error strings with format rules and examples.
  • Updated the existing package-name validation tests in pkg/workflow/argument_injection_test.go to verify:
    • the invalid input is still surfaced, and
    • the new rule/example guidance is present.

return fmt.Errorf(
	"invalid npm package name: %q — npm names must be lowercase alphanumeric and may include hyphens, dots, and underscores (e.g. \"my-package\" or \"@scope/name\")",
	pkg,
)

[Copilot]

Pull request overview

This PR enhances npm and pip package-name validation errors to include inline rule guidance and canonical examples, and updates tests to assert the improved user-facing error text.

Changes:

• Expanded validateNpmPackageName and validatePipPackageName error messages with rule summaries and examples.
• Updated existing validator tests to assert both the rejected value and the new guidance text.
• Updated the generated .github/workflows/agentic_commands.yml header metadata (compiler_version).

Show a summary per file

File	Description
pkg/workflow/name_validation.go	Improves npm/PyPI validation error strings with rule + example guidance.
pkg/workflow/argument_injection_test.go	Strengthens assertions to ensure errors include both the invalid value and guidance text.
.github/workflows/agentic_commands.yml	Regenerated workflow header (compiler_version).

Copilot's findings

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Comments suppressed due to low confidence (1)

pkg/workflow/argument_injection_test.go:360

• The same long expected PyPI guidance string is duplicated across multiple test cases. Consider factoring it into a single const/var used by all invalid-case entries to keep the table concise and reduce maintenance overhead if the wording changes.

		{
			name:        "name starting with hyphen is rejected",
			pkg:         "--index-url=https://attacker.example",
			expectError: true,
			errContains: "PyPI names must start and end with a letter or digit, with hyphens, underscores, or dots allowed inside (e.g. \"requests\" or \"my-package\")",
		},

• Files reviewed: 3/3 changed files
• Comments generated: 3