Fix lens.c compile error: add missing Xft/fontconfig headers

- lens.c: add #include <X11/Xft/Xft.h> and <fontconfig/fontconfig.h>
  (XftFont, XGlyphInfo, etc. were declared but the header was never included)
- quill.c: remove unused flen variable in ed_find_next()
- rigel.c: remove unused get_file() helper (get_fidx() is used throughout)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lens/lens.c

@@ -20,6 +20,8 @@
 #include <X11/Xutil.h>
 #include <X11/Xatom.h>
 #include <X11/keysym.h>
+#include <X11/Xft/Xft.h>
+#include <fontconfig/fontconfig.h>
 #include <Imlib2.h>
 #include <dirent.h>
 #include <stdio.h>