test: add unit tests for ConsoleRuntimeLogger and InMemoryRuntimeLogger (Issue #111)

[rafaio1]

Summary

Adds comprehensive unit tests for both ConsoleRuntimeLogger and InMemoryRuntimeLogger, covering level correctness, metadata handling, insertion order, and console delegation.

Tests Added

• ✅ InMemoryRuntimeLogger records info/error entries with correct level and message
• ✅ Metadata preserved when provided, undefined when omitted
• ✅ Insertion order maintained across mixed calls
• ✅ ConsoleRuntimeLogger delegates to console.info/console.error correctly
• ✅ Empty object passed as metadata fallback for console.error

Verification

All 8 tests pass locally via npx vitest run tests/logger/runtime-logger.test.ts.

Closes #111