song select: folders without an explanation show their song count

The folder board now shows the box explanation lines in place of the song
count. Folders whose box.def has no explanation had an empty board; they show
"N songs" as before.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Scripts/song_select/file_navigator/box_folder.lua

@@ -127,6 +127,9 @@ function SongSelect:draw_folder_board(box, pb, ch_alpha, ch_off, ta, glow_a)
         for _, l in ipairs(box:explanation() or {}) do
             if l ~= "" then lines[#lines + 1] = l end
         end
+        -- folders without an explanation show their song count, as before
+        local n = box.tja_count
+        if #lines == 0 and n and n > 0 then lines[1] = tostring(n) .. " songs" end
         for i, l in ipairs(lines) do
             local ckey = frame .. "\0" .. l
             local label = self._count_cache[ckey]

checksums.sha256

@@ -4733,7 +4733,7 @@ f204455c907d3e0e7affb89db3649a709a27d528d84cc58d51a7d8cfaa1d3deb *./Scripts/back
 4e17bf53815d1e586fdba5f3501d6f2d9935ad5604da871d2e7e89c87499aedd *./Scripts/background/dancer_data/dancer_3.lua
 6e2b3c136611c688cdfbe44b0bbcb9d25c2ab647903246b07f2aef9baa6bab0b *./Scripts/background/dancer_data/dancer_4.lua
 3a4f1f45bb54c4303dc97afcc6f67df831d6d6011a2264baed3d933c789d210e *./Scripts/background/dancer_data/dancer_5.lua
-51ef3eadc4d920efa16b74cbc618571b4472e92a142a8a185fde29d19dfa117a *./Scripts/dan_select/dan_select.lua
+90d725aeea1d3f28b1e4dde631e3d0e50183a7f9b013f80a088dd808bfcd609a *./Scripts/dan_select/dan_select.lua
 f4debb503c757b88627e9011fa835ffc41596523829b619bf56ef0b64f1c16ce *./Scripts/entry/box.lua
 416b87d3691851d2167f9f94dbcdeb1cf39e42f2a8c3bbd9b1700731326338c5 *./Scripts/entry/costume_menu.lua
 d6aa701a8aa437365fb111d62f1e2e9b22195a3bfa5221577b71ced5656049ba *./Scripts/entry/entry.lua
@@ -4767,7 +4767,7 @@ de52279393c43fd2b1f880919597ae6d8802174e0ab6d0db06126b2b090a77b9 *./Scripts/glob
 1eb98ab1463795c77e2f80aa49eaa1aa73e2e4509b739f00ac53d07cbf40fed7 *./Scripts/global/timer.lua
 e0841261cc4dc5bd22c42392708819e9c8d3e25ef1a153d5b7fcae1328347d55 *./Scripts/global/transition.lua
 b458c0c88c2544c93f1402b7506e51c0ca47b67aee2573e130d57c20079c7260 *./Scripts/result/bottom_characters.lua
-5717b0ab0ce1054a4cda3c8074e4f22bec9c96ce379f2a1dd288b4868e637f5d *./Scripts/result/dan_result_draw.lua
+63056cb46b73fcdfcbfb0b51b3afedc3131913935705c6c5d15655db83dde850 *./Scripts/result/dan_result_draw.lua
 5100bbdacb2464227ad50262c5c9daf56ca4ca17dc0aa121fd64bc72946dab8a *./Scripts/result/high_score_indicator.lua
 be8afab142d2a20bd98b0ac22b2d5db474d0a80a5a921c0415fe482c672ee498 *./Scripts/result/result_background.lua
 21ef39a4e4d3906f952922dedd590db7a210a128e7b1e9081b658735052582ef *./Scripts/result/result_bg_layers.lua
@@ -5073,3 +5073,4 @@ c567acc69bf6e9a239e66a195f2d65a7ec6455acff3ee248f4302477d01c193d *./Videos/attra
 3ae7d8f807a3bd693fd4a380e6f6ebedae4d443d796049880f69bc23456a9f85 *./Videos/attract_videos/attractdemo_en_us.mp4
 54f561d89b48feff2fa31999e7485e370f2c55b9f360102b2014310078d20fc3 *./Videos/attract_videos/attractdemo_kor.mp4
 3801f84ff85f56376828abef0b12bd8a1e336b4bc739557bc0ccfa386d79668e *./Videos/op_videos/title.mp4
+095c8d74b3180d101679d2108f89b2806ce377f9fe2050bd5bae54096db6ad91 *./Scripts/dan_select/dan_select_base.lua