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/02-feasibility/exp9.go

@@ -0,0 +1,60 @@
+//go:build ignore
+package main
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"os/exec"
+	"sync"
+	"time"
+)
+
+func run(name, arg string, mu *sync.Mutex, crashed *bool) {
+	cmd := exec.Command("go", "run", "exp9_worker.go", arg)
+	sin, _ := cmd.StdinPipe(); sout, _ := cmd.StdoutPipe()
+	cmd.Stderr = nil
+	cmd.Start()
+	dec := json.NewDecoder(bufio.NewReader(sout))
+	w := bufio.NewWriter(sin); enc := json.NewEncoder(w)
+	held := false
+	for {
+		var q map[string]string
+		if err := dec.Decode(&q); err != nil { break }
+		switch q["method"] {
+		case "stage.lock":   mu.Lock(); held = true; fmt.Printf("  [%s] 获得锁\n", name)
+		case "stage.unlock": if held { mu.Unlock(); held = false; fmt.Printf("  [%s] 释放锁\n", name) }
+		}
+		enc.Encode(map[string]bool{"ok":true}); w.Flush()
+	}
+	err := cmd.Wait()
+	// 关键：进程死了，内核侧检测到 EOF/退出 → 强制释放它持有的锁
+	if held {
+		mu.Unlock()
+		*crashed = true
+		fmt.Printf("  [%s] 进程死亡(%v)，内核强制释放其持有的锁 ← 自愈\n", name, err)
+	}
+}
+
+func main() {
+	fmt.Println("=== 实验 9：持锁进程崩溃后的自愈（验证无需 robust pthread_mutex）===")
+	var mu sync.Mutex
+	crashed := false
+
+	fmt.Println("\n1) 插件 X 拿锁后 panic:")
+	run("X", "crash", &mu, &crashed)
+
+	fmt.Println("\n2) 插件 Y 随后申请同一把锁:")
+	done := make(chan bool, 1)
+	go func() { run("Y", "normal", &mu, new(bool)); done <- true }()
+	select {
+	case <-done:
+		fmt.Println("\n✅ Y 正常获得并释放锁 —— 无死锁")
+		fmt.Println("   → 内核持有锁的所有权，进程死亡由 Wait()/EOF 检测并强制释放")
+		fmt.Println("   → 不需要 PTHREAD_PROCESS_SHARED|ROBUST，也不需要处理 EOWNERDEAD")
+		fmt.Println("   → 整个架构可做到零 cgo")
+	case <-time.After(15 * time.Second):
+		fmt.Println("\n❌ 死锁：Y 拿不到锁（说明需要 robust 语义）")
+	}
+	_ = crashed
+}