feat: restructure plugin system, add Lua plugin support, update docs

internal/plugins/timer/plugin.go

@@ -11,6 +11,7 @@ import (
 )
 
 func init() {
+	plugin.RegisterPluginMeta("timer", "定时任务", "Timer")
 	plugin.RegisterFactory("timer", func(name string, config map[string]interface{}) (sdk.Plugin, error) {
 		return New(name), nil
 	})
@@ -21,6 +22,7 @@ type Plugin struct {
 	mu     sync.Mutex
 	wg     sync.WaitGroup
 	stopCh chan struct{}
+	maxDur time.Duration
 }
 
 type timerTask struct {
@@ -38,6 +40,20 @@ func New(name string) *Plugin {
 func (p *Plugin) Name() string { return p.name }
 
 func (p *Plugin) Start(s *sdk.PluginSDK) error {
+	p.maxDur = 24 * time.Hour
+	s.Settings().RegisterDef(sdk.ConfigDef{
+		Key: "max_duration", Type: "string", DisplayName: "最大定时时长",
+		Description: "允许设置的最大定时时长，例如 24h, 7d, 1h（默认 24h）",
+		Default:     "24h",
+	})
+	if v, _ := s.Settings().Get("max_duration"); v != nil {
+		if s, ok := v.(string); ok && s != "" {
+			if d, err := time.ParseDuration(s); err == nil && d > 0 {
+				p.maxDur = d
+			}
+		}
+	}
+
 	s.RegisterTool("timer_set", sdk.ToolDef{
 		Name:        "timer_set",
 		Description: "设置一个定时提醒。倒计时结束后通过中断通道通知 agent。",
@@ -69,6 +85,9 @@ func (p *Plugin) Start(s *sdk.PluginSDK) error {
 		if err != nil {
 			return map[string]interface{}{"error": fmt.Sprintf("invalid duration %q: %v", durStr, err)}, nil
 		}
+		if dur > p.maxDur {
+			return map[string]interface{}{"error": fmt.Sprintf("duration %v exceeds max %v", dur, p.maxDur)}, nil
+		}
 
 		p.mu.Lock()
 		p.wg.Add(1)