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/fields.go

@@ -0,0 +1,33 @@
+package logger
+
+import "go.uber.org/zap"
+
+// String creates a string field for structured logging.
+func String(key, value string) Field {
+	return zap.String(key, value)
+}
+
+// Int creates an integer field for structured logging.
+func Int(key string, value int) Field {
+	return zap.Int(key, value)
+}
+
+// Int64 creates an int64 field for structured logging.
+func Int64(key string, value int64) Field {
+	return zap.Int64(key, value)
+}
+
+// Bool creates a boolean field for structured logging.
+func Bool(key string, value bool) Field {
+	return zap.Bool(key, value)
+}
+
+// Error creates an error field for structured logging.
+func Error(err error) Field {
+	return zap.Error(err)
+}
+
+// Any creates a field with any value type.
+func Any(key string, value any) Field {
+	return zap.Any(key, value)
+}