fix: 兼容旧 ABI 插件 + 移除 plugin.Open 致命 fallback

- CABINumMin 恢复为 1: 旧工具链编译的插件写入整数 version=1/2,
  与新版内核结构体兼容(仅缺 stage 写回能力), 应允许加载而非拒绝
- tryLoadSO 移除 Go plugin.Open fallback: 本项目插件统一为 c-shared,
  对 c-shared .so 调用 plugin.Open 会 fatal (no plugin module data) 不可恢复,
  直接返回 cabi.Load 错误避免启动崩溃

internal/plugin/dynamic_loader_unix.go

@@ -3,14 +3,10 @@
 package plugin
 
 import (
-	"crypto/sha256"
-	"encoding/hex"
 	"encoding/json"
 	"fmt"
 	"os"
 	"path/filepath"
-	"plugin"
-	"reflect"
 
 	pubsdk "gitcode.com/JianFeeeee/homeagent-sdk/sdk"
 	sdk "gitcode.com/JianFeeeee/HomeAgent/internal/sdk"
@@ -74,53 +70,10 @@ func tryLoadSO(dir, name string, config map[string]interface{}) (sdk.Plugin, err
 	if err == nil {
 		return &cabiPlugin{name: name, handle: handle}, nil
 	}
-
-	data, err := os.ReadFile(soPath)
-	if err != nil {
-		return nil, fmt.Errorf("read %s: %w", soPath, err)
-	}
-	h := sha256.Sum256(data)
-	cacheKey := fmt.Sprintf("plugin_%s_%s.so", name, hex.EncodeToString(h[:8]))
-	cachePath := filepath.Join(os.TempDir(), cacheKey)
-	if _, err := os.Stat(cachePath); os.IsNotExist(err) {
-		if err := os.WriteFile(cachePath, data, 0644); err != nil {
-			return nil, fmt.Errorf("write cache %s: %w", cachePath, err)
-		}
-	}
-
-	p, err := plugin.Open(cachePath)
-	if err != nil {
-		return nil, fmt.Errorf("plugin.Open %s: %w", cachePath, err)
-	}
-
-	sym, err := p.Lookup("NewPlugin")
-	if err != nil {
-		return nil, fmt.Errorf(".so %s must export NewPlugin: %w", soPath, err)
-	}
-
-	rv := reflect.ValueOf(sym)
-	if rv.Kind() != reflect.Func {
-		return nil, fmt.Errorf("NewPlugin in %s is not a function (type=%T)", soPath, sym)
-	}
-	if rv.Type().NumIn() != 2 || rv.Type().NumOut() != 2 {
-		return nil, fmt.Errorf("NewPlugin in %s has wrong arity", soPath)
-	}
-	outs := rv.Call([]reflect.Value{reflect.ValueOf(name), reflect.ValueOf(config)})
-	if len(outs) != 2 {
-		return nil, fmt.Errorf("NewPlugin in %s returned unexpected values", soPath)
-	}
-	if !outs[1].IsNil() {
-		if err, ok := outs[1].Interface().(error); ok {
-			return nil, fmt.Errorf("NewPlugin %s: %w", name, err)
-		}
-		return nil, fmt.Errorf("NewPlugin %s returned non-error second value", name)
-	}
-	plg, ok := outs[0].Interface().(pubsdk.Plugin)
-	if !ok {
-		return nil, fmt.Errorf("NewPlugin in %s does not implement pubsdk.Plugin", soPath)
-	}
-
-	return &dynamicPlugin{name: name, impl: plg}, nil
+	// 本项目插件统一由 plugindev 编译为 c-shared 走 C ABI；
+	// 对 c-shared .so 调用 Go plugin.Open 会 fatal（no plugin module data），
+	// 因此不再 fallback 到 Go plugin，直接返回加载错误避免崩溃。
+	return nil, err
 }
 
 var _ = json.Marshal