Items-list sparklines, retro CSS, pinned tooling, deploy docs

- Bulk-load recent price points per item and render a sparkline in
  the items list (new LoadRecentPriceHistory query avoids N+1).
- Add retro.css visual layer and refreshed login/items/layout styling.
- Swap the logo from webp to avif.
- Pin htmx/Chart.js/Tailwind/templ versions in the Makefile with
  vendor / tools / update-deps targets; README documents the
  dependency-bump flow and the hardened systemd deploy.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

internal/db/queries.go

@@ -798,6 +798,49 @@ func (s *Store) InsertPricePoint(ctx context.Context, p *models.PricePoint) erro
 	return err
 }
 
+// LoadRecentPriceHistory bulk-loads the last `perItem` price points (oldest →
+// newest) for each item id. Returns a map keyed by item id; items with no
+// history are absent from the map. Used by the items list page to render a
+// sparkline per row without N+1 queries.
+func (s *Store) LoadRecentPriceHistory(ctx context.Context, ids []int64, perItem int) (map[int64][]models.PricePoint, error) {
+	out := make(map[int64][]models.PricePoint, len(ids))
+	if len(ids) == 0 || perItem <= 0 {
+		return out, nil
+	}
+	placeholders := make([]string, len(ids))
+	args := make([]any, 0, len(ids)+1)
+	for i, id := range ids {
+		placeholders[i] = "?"
+		args = append(args, id)
+	}
+	args = append(args, perItem)
+	q := `
+		WITH ranked AS (
+			SELECT item_id, price, store, polled_at,
+			       ROW_NUMBER() OVER (PARTITION BY item_id ORDER BY polled_at DESC) AS rn
+			FROM price_history
+			WHERE item_id IN (` + strings.Join(placeholders, ",") + `)
+		)
+		SELECT item_id, price, store, polled_at FROM ranked WHERE rn <= ?
+		ORDER BY item_id, polled_at ASC
+	`
+	rows, err := s.DB.QueryContext(ctx, q, args...)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	for rows.Next() {
+		var p models.PricePoint
+		var store sql.NullString
+		if err := rows.Scan(&p.ItemID, &p.Price, &store, &p.PolledAt); err != nil {
+			return nil, err
+		}
+		p.Store = s.dec(store.String)
+		out[p.ItemID] = append(out[p.ItemID], p)
+	}
+	return out, rows.Err()
+}
+
 func (s *Store) ListPriceHistory(ctx context.Context, itemID int64) ([]models.PricePoint, error) {
 	rows, err := s.DB.QueryContext(ctx,
 		`SELECT id, item_id, price, store, polled_at FROM price_history WHERE item_id = ? ORDER BY polled_at ASC`,

internal/handlers/items.go

@@ -30,11 +30,22 @@ func (a *App) GetItems(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 	cats, _ := a.Store.ListCategories(r.Context())
+
+	// Bulk-load recent price history so each row can render a sparkline
+	// without N+1 queries. 20 points is enough for a meaningful trend line
+	// at 80px wide and stays cheap on the largest realistic watchlists.
+	ids := make([]int64, 0, len(items))
+	for _, it := range items {
+		ids = append(ids, it.ID)
+	}
+	history, _ := a.Store.LoadRecentPriceHistory(r.Context(), ids, 20)
+
 	render(w, r, templates.Items(templates.ItemsData{
 		Page:             a.page(r, "Items", "items"),
 		Items:            items,
 		Categories:       cats,
 		SelectedCategory: cat,
+		PriceHistory:     history,
 	}))
 }
 
@@ -387,7 +398,8 @@ func (a *App) PostToggleItem(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	a.Scheduler.SyncItem(*it)
-	render(w, r, templates.ItemRow(*it, a.Auth.CSRFToken(r.Context())))
+	hist, _ := a.Store.LoadRecentPriceHistory(r.Context(), []int64{id}, 20)
+	render(w, r, templates.ItemRow(*it, a.Auth.CSRFToken(r.Context()), hist[id]))
 }
 
 func (a *App) PostDeleteItem(w http.ResponseWriter, r *http.Request) {