fix: Web Widget SDK + Auto-Reply AgentBot sender + LLM 真实模型对接

## 核心修复

### 1. Auto-Reply Sender 修复（所有渠道）
- AutoReplyListener.sendAutoReply() 通过 botInboxRepo 查询 inbox 关联的 AgentBot
- 使用正确的 SenderType="AgentBot"（非小写 agent_bot）传递真实 AgentBot ID
- bootstrap 注入 agentBotInboxRepo/agentBotRepo 依赖

### 2. 事件数据 BUG 修复（影响所有 Webhook 渠道）
- incoming_persister.dispatch(): 补全 sender_type/content 到 event.Data
- channel/webhook.go: HandleWebhook 同步分发也补全 sender_type/content
- 未补全前 AutoReplyListener 找不到字段直接跳过

### 3. Web Widget SDK 生产验证修复
- cookie → localStorage token 同步（frontend/index.html）
- 路由双注册修复（router.go）
- Vite SPA 模式 + /widget 重写（vite.config.ts）
- WidgetService 注入 Dispatcher 触发事件分发

### 4. LLM 真实模型对接
- 配置 deepseek-v4-flash @ http://10.58.144.6:2014/v1
- LLM-mode auto-reply 规则创建并验证通过
- Prompt 文档落地: docs/captain-ai-auto-replay-prompt.md

### 5. 新增基础设施
- Helm chart (deploy/helm/)
- Widget SDK 生产测试页面
- QA 报告

Closes: BUG-W2 (auth sync), BUG-W3 (route double-reg),
       BUG-WEBHOOK-EVENT (missing event data fields)

backend/internal/handler/webhook/incoming_persister.go

@@ -15,6 +15,7 @@ import (
 	"github.com/gochat/gochat/internal/channel"
 	"github.com/gochat/gochat/internal/model"
 	"github.com/gochat/gochat/internal/worker"
+	applogger "github.com/gochat/gochat/pkg/logger"
 )
 
 // IncomingPersister is the durable boundary after provider-specific webhook parsing.
@@ -425,11 +426,15 @@ func (p *IncomingPersister) dispatch(ctx context.Context, eventType channel.Even
 		}
 		if result.Message != nil {
 			event.Data["message"] = result.Message
+			event.Data["sender_type"] = result.Message.SenderType
+			event.Data["content"] = result.Message.Content
 		}
 	}
 	if message != nil {
 		event.ConversationID = message.ConversationID
 		event.Data["message"] = message
+		event.Data["sender_type"] = message.SenderType
+		event.Data["content"] = message.Content
 		if message.SenderID != nil {
 			event.ContactID = *message.SenderID
 		}
@@ -438,6 +443,8 @@ func (p *IncomingPersister) dispatch(ctx context.Context, eventType channel.Even
 	if err := p.dispatcher.DispatchAsync(ctx, event); err != nil {
 		// Chatwoot's async side effects should not make provider webhooks fail.
 		_ = err
+		applogger.L().Warnf("IncomingPersister: failed to dispatch %s event for inbox=%d: %v",
+			eventType, inbox.ID, err)
 	}
 }