docs(plugin-arch): 归档插件架构迁移评估 + plan 第11节整改计划

- docs/zh/架构迁移评估.md: C ABI→子进程+共享内存完整迁移论证(1621行)
- docs/zh/experiments/: 18项可复跑可行性实验(架构评估的所有数字来源)
- plan.md §11: 11.1~11.9 插件架构缺陷修复清单(唯一权威编号)
- main 保持干净,本批次为 update 特性分支的整改起点

docs/zh/experiments/plugin-arch/01-dlclose-nodelete/exp01a/main.go

@@ -0,0 +1,72 @@
+//go:build ignore
+
+package main
+
+/*
+#cgo LDFLAGS: -ldl
+#include <dlfcn.h>
+#include <stdlib.h>
+typedef const char* (*verfn)(void);
+static const char* call_ver(void* f){ return ((verfn)f)(); }
+*/
+import "C"
+import (
+	"fmt"
+	"os"
+	"unsafe"
+)
+
+func main() {
+	// Go 用 dlopen 加载纯 C shim（shim 本身常驻，无所谓）
+	sp := C.CString("./shim.so")
+	shim := C.dlopen(sp, C.RTLD_NOW|C.RTLD_LOCAL)
+	C.free(unsafe.Pointer(sp))
+	if shim == nil {
+		fmt.Println("shim 加载失败:", C.GoString(C.dlerror()))
+		os.Exit(1)
+	}
+	openName := C.CString("shim_open")
+	closeName := C.CString("shim_close")
+	symName := C.CString("shim_sym")
+	shimOpen := C.dlsym(shim, openName)
+	shimClose := C.dlsym(shim, closeName)
+	shimSym := C.dlsym(shim, symName)
+	C.free(unsafe.Pointer(openName))
+	C.free(unsafe.Pointer(closeName))
+	C.free(unsafe.Pointer(symName))
+	fmt.Printf("shim 就绪: open=%p close=%p sym=%p\n\n", shimOpen, shimClose, shimSym)
+
+	// 直接用 dlopen/dlsym 调 shim 的三个函数（避免再写一层 C 包装）
+	load := func(path string) unsafe.Pointer {
+		cp := C.CString(path)
+		defer C.free(unsafe.Pointer(cp))
+		return C.dlopen(cp, C.RTLD_NOW|C.RTLD_LOCAL)
+	}
+	ver := func(h unsafe.Pointer) string {
+		n := C.CString("probe_version")
+		defer C.free(unsafe.Pointer(n))
+		f := C.dlsym(h, n)
+		if f == nil { return "<no sym>" }
+		return C.GoString(C.call_ver(f))
+	}
+
+	fmt.Println("--- 场景: Go(带 NODELETE runtime) 加载/卸载纯 C 的第三层 so ---")
+	h1 := load("./probe.so")
+	fmt.Printf("1) dlopen probe.so       handle=%p  version=%s\n", h1, ver(h1))
+
+	rc := C.dlclose(h1)
+	fmt.Printf("2) dlclose               rc=%d\n", int(rc))
+
+	// 换内容（V1 -> V2），同路径
+	in, _ := os.ReadFile("probe_v2.so")
+	os.WriteFile("probe.so", in, 0755)
+	fmt.Println("3) 磁盘 probe.so 内容替换为 V2（同路径）")
+
+	h2 := load("./probe.so")
+	fmt.Printf("4) 再 dlopen 同路径       handle=%p  version=%s\n", h2, ver(h2))
+	if h1 == h2 {
+		fmt.Println("   => 句柄相同：未卸载，仍是旧代码")
+	} else {
+		fmt.Println("   => 句柄不同：真正卸载并重新装载了新代码 ✅")
+	}
+}