Summary

Adds a shared logger package to toolhive-core for use by ToolHive Runtime, Registry, and other ToolHive ecosystem projects.

Related to stacklok/toolhive#3614

Changes

• Added logger package with structured logging capabilities
• Supports both structured (JSON) and unstructured (human-readable) output
• Integration with logr.Logger for Kubernetes controller compatibility
• Configurable debug mode via DebugProvider interface
• Environment-based configuration via UNSTRUCTURED_LOGS env var
• Added comprehensive test coverage

Features

The logger package provides:

• Multiple log levels: Debug, Info, Warn, Error, Panic, DPanic, Fatal
• Flexible output: Structured JSON or unstructured human-readable format
• Kubernetes integration: NewLogr() for controller-runtime compatibility
• Dependency injection: DebugProvider interface for configurable debug mode
• Testing support: InitializeWithOptions() for test isolation

API

// Initialize with default (non-debug) mode
logger.Initialize()

// Initialize with custom debug provider
logger.InitializeWithDebug(myDebugProvider)

// Initialize with full options for testing
logger.InitializeWithOptions(envReader, debugProvider)

// Logging functions
logger.Debug("message")
logger.Debugf("format %s", arg)
logger.Debugw("message", "key", value)
// ... same pattern for Info, Warn, Error, Panic, DPanic, Fatal

Testing

• go build ./... succeeds
• go test ./... passes

AI Transparency

This PR was created with the assistance of AI (Claude by Anthropic) for code generation and review.