feat: implement Epic 0 - Project Setup & Foundation

Implemented all 5 stories from Epic 0:

Story 0.1: Project Initialization
- Initialize Go module with path git.dcentral.systems/toolz/goplt
- Create complete directory structure (cmd/, internal/, pkg/, modules/, config/, etc.)
- Add comprehensive .gitignore for Go projects
- Create README.md with project overview and setup instructions

Story 0.2: Configuration Management System
- Define ConfigProvider interface in pkg/config
- Implement Viper-based configuration in internal/config
- Create configuration loader with environment support
- Add default, development, and production YAML config files

Story 0.3: Structured Logging System
- Define Logger interface in pkg/logger
- Implement Zap-based logger in internal/logger
- Add request ID middleware for Gin
- Create global logger export with convenience functions
- Support context-aware logging with request/user ID extraction

Story 0.4: CI/CD Pipeline
- Create GitHub Actions workflow for CI (test, lint, build, fmt)
- Add comprehensive Makefile with development commands
- Configure golangci-lint with reasonable defaults

Story 0.5: Dependency Injection and Bootstrap
- Create FX-based DI container in internal/di
- Implement provider functions for Config and Logger
- Create application entry point in cmd/platform/main.go
- Add lifecycle management with graceful shutdown

All acceptance criteria met:
- go build ./cmd/platform succeeds
- go test ./... runs successfully
- go mod verify passes
- Config loads from config/default.yaml
- Logger can be injected and used
- Application starts and shuts down gracefully

pkg/logger/logger.go

@@ -0,0 +1,33 @@
+package logger
+
+import (
+	"context"
+)
+
+// Field represents a key-value pair for structured logging.
+// This is an alias for zap.Field to maintain compatibility with zap.
+type Field = interface{}
+
+// Logger defines the interface for structured logging.
+// It provides methods for logging at different levels with structured fields.
+type Logger interface {
+	// Debug logs a message at debug level with optional fields.
+	Debug(msg string, fields ...Field)
+
+	// Info logs a message at info level with optional fields.
+	Info(msg string, fields ...Field)
+
+	// Warn logs a message at warning level with optional fields.
+	Warn(msg string, fields ...Field)
+
+	// Error logs a message at error level with optional fields.
+	Error(msg string, fields ...Field)
+
+	// With creates a child logger with the specified fields.
+	// All subsequent log calls will include these fields.
+	With(fields ...Field) Logger
+
+	// WithContext creates a child logger with fields extracted from context.
+	// Typically extracts request ID, user ID, and other context values.
+	WithContext(ctx context.Context) Logger
+}