feat: paginate and search brand questions across selects

Make GET /api/tenant/brands/:id/questions return a paginated
QuestionListResponse (items/total/page/page_size) with optional `q`
full-text filter, validated page/page_size query params, and per-params
cache keys. Add a usePaginatedBrandQuestions composable backing the
imitation, template-wizard, and tracking question selects with
search-as-you-type and infinite scroll, plus ensure-loaded-by-id so a
deep-linked or pre-selected question is fetched even when off the first
page. Brands view now drives its questions table via server pagination.

Also redesign the Tracking hot-questions and cited-articles lists
(mention-rate badges/bars, metric groups, refreshed styling) and fall
back to citation-fact article_id/title when no high-confidence URL alias
matches, so cited articles surface even without an alias row.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

server/internal/tenant/transport/brand_handler.go

@@ -156,14 +156,39 @@ func (h *BrandHandler) DeleteKeyword(c *gin.Context) {
 
 // Questions
 func (h *BrandHandler) ListQuestions(c *gin.Context) {
-	brandID, _ := strconv.ParseInt(c.Param("id"), 10, 64)
+	brandID, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil {
+		response.Error(c, response.ErrBadRequest(40001, "invalid_id", "brand id must be a number"))
+		return
+	}
+
 	var keywordID *int64
 	if v := c.Query("keyword_id"); v != "" {
-		if id, err := strconv.ParseInt(v, 10, 64); err == nil {
-			keywordID = &id
+		id, parseErr := strconv.ParseInt(v, 10, 64)
+		if parseErr != nil || id <= 0 {
+			response.Error(c, response.ErrBadRequest(40001, "invalid_params", "keyword_id must be a positive integer"))
+			return
 		}
+		keywordID = &id
 	}
-	data, err := h.svc.ListQuestions(c.Request.Context(), brandID, keywordID)
+
+	page, err := parsePositiveIntQuery(c, "page", 1)
+	if err != nil {
+		response.Error(c, response.ErrBadRequest(40001, "invalid_params", "page must be a positive integer"))
+		return
+	}
+	pageSize, err := parsePositiveIntQuery(c, "page_size", 10)
+	if err != nil {
+		response.Error(c, response.ErrBadRequest(40001, "invalid_params", "page_size must be a positive integer"))
+		return
+	}
+
+	data, err := h.svc.ListQuestions(c.Request.Context(), brandID, app.QuestionListParams{
+		KeywordID: keywordID,
+		Page:      page,
+		PageSize:  pageSize,
+		Query:     c.Query("q"),
+	})
 	if err != nil {
 		response.Error(c, err)
 		return
@@ -171,6 +196,21 @@ func (h *BrandHandler) ListQuestions(c *gin.Context) {
 	response.Success(c, data)
 }
 
+func parsePositiveIntQuery(c *gin.Context, key string, fallback int) (int, error) {
+	raw := c.Query(key)
+	if raw == "" {
+		return fallback, nil
+	}
+	value, err := strconv.Atoi(raw)
+	if err != nil || value <= 0 {
+		if err != nil {
+			return 0, err
+		}
+		return 0, strconv.ErrSyntax
+	}
+	return value, nil
+}
+
 func (h *BrandHandler) CreateQuestion(c *gin.Context) {
 	brandID, _ := strconv.ParseInt(c.Param("id"), 10, 64)
 	var req app.QuestionRequest