feat(core): add typed eventbus and domain extension points

core/contracts/logger.go

@@ -0,0 +1,35 @@
+package contracts
+
+import (
+	"context"
+)
+
+// LoggerService defines the contract for structured logging with trace ID and context correlation.
+type LoggerService interface {
+	// Debug logs a debug message with optional key-value structured fields.
+	Debug(ctx context.Context, msg string, keysAndValues ...any)
+
+	// Info logs an informational message with optional key-value structured fields.
+	Info(ctx context.Context, msg string, keysAndValues ...any)
+
+	// Warn logs a warning message with optional key-value structured fields.
+	Warn(ctx context.Context, msg string, keysAndValues ...any)
+
+	// Error logs an error message with optional key-value structured fields.
+	Error(ctx context.Context, msg string, keysAndValues ...any)
+
+	// Debugf logs a formatted debug message.
+	Debugf(ctx context.Context, format string, args ...any)
+
+	// Infof logs a formatted informational message.
+	Infof(ctx context.Context, format string, args ...any)
+
+	// Warnf logs a formatted warning message.
+	Warnf(ctx context.Context, format string, args ...any)
+
+	// Errorf logs a formatted error message.
+	Errorf(ctx context.Context, format string, args ...any)
+
+	// With returns a child logger enriched with additional key-value attributes.
+	With(keysAndValues ...any) LoggerService
+}