feat(runner): implement cluster mode with Redis-based task dispatching and registry

Introduce a distributed task execution system for gRPC runners. This includes:
- A `TaskBus` for cluster-mode task dispatching via Redis Pub/Sub.
- A `RunnerRegistry` to track active runner instances in Redis.
- Support for both standalone and cluster modes via configuration.
- Refactored `RunnerHub` and `TaskManager` to use a `TaskDispatcher` interface, decoupling task submission from local execution.
- Added distributed locking to `HotRankWorker` to ensure only one instance performs periodic hot rank recalculations in a multi-instance deployment.
- Updated dependency injection (Wire) to support the new runner components and registry.

internal/config/runner.go

@@ -0,0 +1,28 @@
+package config
+
+// RunnerConfig Runner 集群配置
+type RunnerConfig struct {
+	Mode    string              `mapstructure:"mode"` // "standalone" | "cluster"，空则跟随 websocket.mode
+	Cluster RunnerClusterConfig `mapstructure:"cluster"`
+}
+
+// RunnerClusterConfig Runner 集群模式配置
+type RunnerClusterConfig struct {
+	InstanceID        string `mapstructure:"instance_id"`         // 空则跟随 websocket.cluster.instance_id
+	TaskChannel       string `mapstructure:"task_channel"`
+	ResultChannel     string `mapstructure:"result_channel"`
+	RegistryPrefix    string `mapstructure:"registry_prefix"`
+	CapPrefix         string `mapstructure:"cap_prefix"`
+	RegistryTTL       int    `mapstructure:"registry_ttl"`
+	HeartbeatInterval int    `mapstructure:"heartbeat_interval"`
+}
+
+// ApplyWSDefaults 用 WebSocket 配置填充 Runner 中未设置的共享字段
+func (r *RunnerConfig) ApplyWSDefaults(ws WSConfig) {
+	if r.Mode == "" {
+		r.Mode = ws.Mode
+	}
+	if r.Cluster.InstanceID == "" {
+		r.Cluster.InstanceID = ws.Cluster.InstanceID
+	}
+}