fun: HTTP RPC framework with DI, guards, streams and codegen

- Service binding via reflection with 4 method signatures
- Dependency injection (Wired/auto tags) and guards
- Streamable HTTP (NDJSON) streaming responses
- Go/TypeScript client code generation (self-contained, with interceptors)
- Enum support, structured Result, logging
- 16 regression tests covering all fixed bugs

enum.go

@@ -0,0 +1,26 @@
+package fun
+
+import (
+	"errors"
+	"reflect"
+)
+
+type enum interface {
+	Names() []string
+}
+
+type displayEnum interface {
+	DisplayNames() []string
+	Names() []string
+}
+
+var (
+	enumType        = reflect.TypeFor[enum]()
+	displayEnumType = reflect.TypeFor[displayEnum]()
+)
+
+var (
+	errMethodNotFound = errors.New("method not found")
+	errEmptyFields    = errors.New("serviceName and methodName cannot be empty")
+	errDTORequired    = errors.New("method requires a DTO but none provided")
+)