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/exp11.go

@@ -0,0 +1,42 @@
+//go:build ignore
+package main
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"os/exec"
+	"sort"
+	"time"
+)
+
+type Req struct{ ID int `json:"id"`; Method string `json:"method"`; Args json.RawMessage `json:"args"` }
+type Res struct{ ID int `json:"id"`; Result string `json:"result"` }
+
+func main() {
+	fmt.Println("=== 实验 11：工具调用 RPC 端到端延迟（实测 payload 中位 93B）===")
+	cmd := exec.Command("./plug11")
+	sin, _ := cmd.StdinPipe(); sout, _ := cmd.StdoutPipe()
+	cmd.Start()
+	enc := json.NewEncoder(bufio.NewWriter(sin))
+	w := bufio.NewWriter(sin); enc = json.NewEncoder(w)
+	dec := json.NewDecoder(bufio.NewReader(sout))
+
+	args := json.RawMessage(`{"city":"hangzhou","days":3,"unit":"celsius","detail":true}`)
+	const N = 10000
+	lat := make([]time.Duration, 0, N)
+	for i := 0; i < N; i++ {
+		t0 := time.Now()
+		enc.Encode(Req{ID: i, Method: "weather_query", Args: args}); w.Flush()
+		var r Res
+		if err := dec.Decode(&r); err != nil { break }
+		lat = append(lat, time.Since(t0))
+	}
+	sin.Close(); cmd.Wait()
+	sort.Slice(lat, func(a,b int) bool { return lat[a] < lat[b] })
+	p := func(q float64) time.Duration { return lat[int(float64(len(lat))*q)] }
+	fmt.Printf("样本 %d 次\n", len(lat))
+	fmt.Printf("  p50 = %v\n  p90 = %v\n  p99 = %v\n  max = %v\n", p(0.5), p(0.9), p(0.99), lat[len(lat)-1])
+	fmt.Printf("\n对照 LLM 单轮往返 2-8 秒 → RPC 占比 ≈ %.5f%%\n",
+		float64(p(0.5))/float64(3*time.Second)*100)
+}