feat(lists): replace category buttons with dynamic hashtag categories and group open items by hashtag

internal/storage/sqlite.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"regexp"
 	"strings"
 	"sync"
 	"time"
@@ -1887,12 +1888,28 @@ func (s *Store) CreateListItem(listID, content, category, quantity string, sortO
 	if content == "" {
 		return nil, errors.New("item content cannot be empty")
 	}
+
+	category = strings.TrimSpace(category)
+	// Auto-extract hashtag if category is empty
+	if category == "" && strings.Contains(content, "#") {
+		re := regexp.MustCompile(`#([a-zA-Z0-9äöüÄÖÜß_-]+)`)
+		if m := re.FindStringSubmatch(content); len(m) > 1 {
+			category = m[1]
+			cleaned := strings.TrimSpace(re.ReplaceAllString(content, ""))
+			if cleaned != "" {
+				content = cleaned
+			}
+		}
+	} else if category != "" {
+		category = strings.TrimPrefix(category, "#")
+	}
+
 	now := domain.NowISO()
 	it := &domain.ListItem{
 		ID:          domain.NewID("itm"),
 		ListID:      listID,
 		Content:     content,
-		Category:    strings.TrimSpace(category),
+		Category:    category,
 		Quantity:    strings.TrimSpace(quantity),
 		IsCompleted: false,
 		SortOrder:   sortOrder,