Enhance dashboard summary and statistics with new fields and caching improvements

- Added new field `Days` and `ScrapedTED` to `SummaryResponse` for tracking daily TED scrape counts.
- Updated `SummaryQuery` to include `Days` parameter for querying scraped TED data.
- Modified `Summary` handler to accept and process the new `Days` parameter.
- Refactored `Summary` method in the repository to support the new `Days` parameter and improved aggregation logic.
- Enhanced caching logic in the service layer to utilize a composite cache key based on `closingWindowSec` and `days`, improving cache management and retrieval efficiency.

This update improves the dashboard's functionality by providing more detailed insights into TED scraping activities and optimizing the caching strategy for better performance.

internal/dashboard/handler.go

@@ -19,10 +19,11 @@ func NewHandler(service Service) *Handler {
 
 // Summary returns top-level dashboard counters.
 // @Summary Dashboard summary
-// @Description Top-level counters for hero pills and stat cards
+// @Description Top-level counters for hero pills and stat cards, including daily TED scrape counts
 // @Tags Admin-Dashboard
 // @Produce json
 // @Param closing_window query int false "Hours considered closing soon (default 168)"
+// @Param days query int false "Days back for scraped TED daily series (default 14, max 90)"
 // @Success 200 {object} response.APIResponse{data=SummaryResponse}
 // @Failure 500 {object} response.APIResponse
 // @Router /admin/v1/dashboard/summary [get]
@@ -30,6 +31,7 @@ func NewHandler(service Service) *Handler {
 func (h *Handler) Summary(c echo.Context) error {
 	query := SummaryQuery{
 		ClosingWindow: parseIntQuery(c, "closing_window", 0),
+		Days:          parseIntQuery(c, "days", 0),
 	}
 
 	out, err := h.service.Summary(c.Request().Context(), query)
@@ -37,7 +39,7 @@ func (h *Handler) Summary(c echo.Context) error {
 		return response.InternalServerError(c, "Failed to load dashboard summary")
 	}
 
-	setPrivateCache(c, 60)
+	setPrivateCache(c, 300)
 	return response.Success(c, out, "Dashboard summary retrieved successfully")
 }
 
@@ -163,7 +165,7 @@ func (h *Handler) Recent(c echo.Context) error {
 
 // Statistics returns scraping and translation statistics for charts.
 // @Summary Dashboard statistics report
-// @Description Daily and lifetime statistics for TED scraping, document scraping, and AI translation
+// @Description Daily and lifetime statistics for document scraping and AI translation
 // @Tags Admin-Dashboard
 // @Produce json
 // @Param days query int false "Days back for daily series (default 14, max 90)"