feat(webui): add minimal dashboard (Pico.css) with tail, trigger, status; JSON endpoints: /api/info,/api/channels,/api/tail,/api/trigger; default compose/UI auth via HTTP_TOKEN

internal/store/store.go

@@ -67,6 +67,24 @@ func (s *Store) InsertMessage(ctx context.Context, m Message) error {
 	return err
 }
 
+// ListChannels returns distinct channel identifiers seen in the database.
+func (s *Store) ListChannels(ctx context.Context) ([]string, error) {
+	rows, err := s.db.QueryContext(ctx, "SELECT DISTINCT channel FROM messages ORDER BY lower(channel)")
+	if err != nil {
+ 		return nil, err
+ 	}
+ 	defer rows.Close()
+ 	var out []string
+ 	for rows.Next() {
+ 		var ch string
+ 		if err := rows.Scan(&ch); err != nil {
+ 			return nil, err
+ 		}
+ 		out = append(out, ch)
+ 	}
+ 	return out, rows.Err()
+}
+
 func nullIfEmpty(s string) any {
 	if s == "" {
 		return nil