refactor: rebrand from cs-agent to BossChat

- Rename Go module: cs-agent → bosschat
- Rename all import paths across 200+ Go files
- Rename SDK: cs-ai-agent-sdk → bosschat-sdk
- Rename message protocol: cs-agent:* → bosschat:*
- Rename JS globals: CSAgentConfig → BossChatConfig
- Rename CSS classes: cs-agent-* → bosschat-*
- Update Makefile APP_NAME and ARCHIVE_NAME
- Update logo assets
- Fix display name: BoosChat → BossChat

cmd/testdata/channel/init.go

@@ -1,10 +1,10 @@
 package channel
 
 import (
-	"cs-agent/internal/models"
-	"cs-agent/internal/pkg/dto"
-	"cs-agent/internal/pkg/enums"
-	"cs-agent/internal/repositories"
+	"bosschat/internal/models"
+	"bosschat/internal/pkg/dto"
+	"bosschat/internal/pkg/enums"
+	"bosschat/internal/repositories"
 	"fmt"
 	"time"
 
@@ -66,7 +66,7 @@ func buildSeedItems(aiAgentID int64) []models.Channel {
 			AIAgentID:   aiAgentID,
 			ConfigJSON: jsons.ToJsonStr(dto.WebChannelConfig{
 				Title:      "在线客服",
-				Subtitle:   "BoosChat 提供技术支持",
+				Subtitle:   "BossChat 提供技术支持",
 				ThemeColor: "#2563eb",
 				Position:   "right",
 				Width:      "780px",