Redesign dashboard: refined-minimal layout with product thumbnails

Move the dashboard from boxed glass cards to an airy, hairline-separated
layout where type and whitespace carry the page, then surface listing
images as the visual anchor.

- Solid surfaces (drop backdrop-filter glass, per spec); calm flat field
  with a single cool top-glow replacing the drifting aurora and dot-grid.
- Recent results / recent alerts are now product feeds with 52px
  thumbnails, listing titles, and price; image_url threaded through
  ResultRow/AlertRow (data already stored, just unsurfaced).
- ListResults gains an OnlyAlerted filter so the alerts panel reuses its
  decryption path instead of a raw query.
- Dashboard recent results capped at 8 for a balanced snapshot.

internal/handlers/dashboard.go

@@ -1,9 +1,7 @@
 package handlers
 
 import (
-	"database/sql"
 	"net/http"
-	"time"
 
 	"veola/internal/db"
 	"veola/templates"
@@ -36,7 +34,7 @@ func (a *App) dashboardData(r *http.Request) (templates.DashboardData, error) {
 	if err != nil {
 		return templates.DashboardData{}, err
 	}
-	results, err := a.Store.ListResults(r.Context(), db.ResultsQuery{Limit: 20, ExcludeEnded: true})
+	results, err := a.Store.ListResults(r.Context(), db.ResultsQuery{Limit: 8, ExcludeEnded: true})
 	if err != nil {
 		return templates.DashboardData{}, err
 	}
@@ -55,6 +53,7 @@ func (a *App) dashboardData(r *http.Request) (templates.DashboardData, error) {
 			Currency: r.Currency,
 			Source:   r.Source,
 			URL:      r.URL,
+			ImageURL: r.ImageURL,
 			FoundAt:  r.FoundAt,
 			Alerted:  r.Alerted,
 		})
@@ -80,36 +79,20 @@ func (a *App) dashboardData(r *http.Request) (templates.DashboardData, error) {
 }
 
 func alertsRecent(a *App, r *http.Request, itemNames map[int64]string) ([]templates.AlertRow, error) {
-	rows, err := a.Store.DB.QueryContext(r.Context(), `
-		SELECT item_id, price, currency, found_at FROM results
-		WHERE alerted = 1 ORDER BY found_at DESC LIMIT 5
-	`)
+	results, err := a.Store.ListResults(r.Context(), db.ResultsQuery{OnlyAlerted: true, Limit: 5})
 	if err != nil {
 		return nil, err
 	}
-	defer rows.Close()
-	var out []templates.AlertRow
-	for rows.Next() {
-		var (
-			itemID   int64
-			price    sql.NullFloat64
-			currency string
-			foundAt  time.Time
-		)
-		if err := rows.Scan(&itemID, &price, &currency, &foundAt); err != nil {
-			return nil, err
-		}
-		var p *float64
-		if price.Valid {
-			v := price.Float64
-			p = &v
-		}
+	out := make([]templates.AlertRow, 0, len(results))
+	for _, res := range results {
 		out = append(out, templates.AlertRow{
-			ItemName: itemNames[itemID],
-			Price:    p,
-			Currency: currency,
-			FoundAt:  foundAt,
+			ItemName: itemNames[res.ItemID],
+			Title:    res.Title,
+			Price:    res.Price,
+			Currency: res.Currency,
+			ImageURL: res.ImageURL,
+			FoundAt:  res.FoundAt,
 		})
 	}
-	return out, rows.Err()
+	return out, nil
 }