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

text.go

@@ -0,0 +1,25 @@
+// 文本处理辅助方法
+
+package fun
+
+import "unicode"
+
+// 首字母转大写
+func firstLetterToUpper(s string) string {
+	if len(s) == 0 {
+		return s
+	}
+	runes := []rune(s)
+	runes[0] = unicode.ToUpper(runes[0])
+	return string(runes)
+}
+
+// 首字母转小写
+func firstLetterToLower(s string) string {
+	if len(s) == 0 {
+		return s
+	}
+	runes := []rune(s)
+	runes[0] = unicode.ToLower(runes[0])
+	return string(runes)
+}