feat(ECR-041): OpsCMS Banner 薄写面（Write-Wave 首刀）

Admin POST/PUT + admin.cms.write/审计；C 端 GET /home/banners；首页投影回退静态 homeFeeds；migration 000051；不碰 FeedSlot/支付/UGC。

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/api/internal/handler/home.go

@@ -20,6 +20,7 @@ type HomeHandler struct {
 func (h *HomeHandler) Register(api *gin.RouterGroup) {
 	g := api.Group("/home")
 	g.GET("/tools", h.Tools)
+	g.GET("/banners", h.Banners)
 	g.GET("/daily-tips", h.DailyTips)
 }
 
@@ -35,6 +36,16 @@ func (h *HomeHandler) Tools(c *gin.Context) {
 	response.OK(c, gin.H{"items": items})
 }
 
+func (h *HomeHandler) Banners(c *gin.Context) {
+	placement := c.DefaultQuery("placement", "home")
+	items, err := h.Svc.ListPublicBanners(c.Request.Context(), placement)
+	if err != nil {
+		response.Fail(c, http.StatusInternalServerError, 50046, "home banners failed")
+		return
+	}
+	response.OK(c, gin.H{"items": items})
+}
+
 func (h *HomeHandler) DailyTips(c *gin.Context) {
 	uid, _ := middleware.UserIDFromContext(c)
 	tips, err := h.Svc.DailyTips(c.Request.Context(), uid)