feat: add validation and semver utility modules

[AdekunleBamz]

Summary

This PR adds two comprehensive utility modules to enhance input validation and semantic versioning operations for the lerna release action.

Changes

New Files

src/utils/validation.ts - Input validation utilities:

• isValidPackageName() - Validates npm package naming conventions (scoped and unscoped)
• getPackageScope() - Extracts scope from scoped package names
• getUnscopedName() - Gets the unscoped portion of a package name
• isNonEmptyString() - Type guard for non-empty strings
• validatePackagesCsv() - Parses and validates comma-separated package lists
• isValidBranchName() - Validates git branch naming rules
• isValidGitHubTokenFormat() - Validates GitHub token format (PAT, OAuth, App tokens)
• sanitizeForShell() - Removes dangerous shell characters from input
• isValidWorkflowId() - Validates workflow filename or numeric ID format
• isValidCommitType() - Validates conventional commit types
• assertInput() - Assertion helper with descriptive error messages

src/utils/semver.ts - Semantic versioning utilities:

• isValidSemVer() - Validates semantic version strings
• parseSemVer() / formatSemVer() - Parse and format SemVer objects
• compareSemVer() - Compare two versions (supports prereleases)
• sortSemVer() - Sort version arrays ascending or descending
• getHighestVersion() / getLowestVersion() - Find version extremes
• bumpVersion() - Increment versions (major/minor/patch/pre*)
• satisfiesGte() / satisfiesLt() - Version range checking
• isPrerelease() - Detect prerelease versions
• extractVersionFromTag() - Extract version from git tags like @scope/pkg@1.0.0
• getStableVersions() / getPrereleaseVersions() - Filter version lists
• getPrereleaseIdentifier() - Extract prerelease identifier (alpha, beta, etc.)

Test Coverage

• 47 tests for validation utilities
• 46 tests for semver utilities
• All 197 total tests pass

Benefits

• Input Safety: Helps prevent injection attacks and validate user inputs before processing
• Version Management: Enables intelligent version handling for release workflows
• Reusability: Well-typed utilities that can be used across the codebase
• Maintainability: Follows existing project patterns and code style