Save best scores and last difficulty to a JSON profile

- profile package: best moves, best time and games played per
  deck/difficulty, stored in the user data folder
- Win panel shows the best (or New best!), language menu shows bests
- Profile memory always comes from the heap allocator (it outlives callers)

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

src/screens/screens.odin

@@ -1,10 +1,13 @@
 package screens
 
+import "core:fmt"
 import "core:math"
+import "core:strings"
 import raylib "vendor:raylib"
 import card "../card"
 import decks "../decks"
 import memory "../memory"
+import profile "../profile"
 import themes "../themes"
 import ui "../ui"
 
@@ -100,21 +103,26 @@ language_menu :: proc(language: decks.Language, difficulty: ^memory.Difficulty)
         if ui.button(rect, decks.DECKS[deck].name, theme.primary, hotkey = keys[i]) {
             result = deck
         }
-        ui.draw_text_centered(decks.DECKS[deck].native, x + button_w / 2, 450, 22, theme.ink, info.symbol_style)
+        ui.draw_text_centered(decks.DECKS[deck].native, x + button_w / 2, 448, 22, theme.ink, info.symbol_style)
+        best_text := cstring("No games yet")
+        if record, ok := profile.get(memory.score_key(deck, difficulty^)); ok {
+            best_text = strings.clone_to_cstring(fmt.tprintf("Best  %d moves  ·  %s", record.best_moves, profile.format_time(record.best_seconds)), context.temp_allocator)
+        }
+        ui.draw_text_centered(best_text, x + button_w / 2, 476, 17, raylib.Fade(theme.ink, 0.65))
         x += button_w + gap
     }
 
     // Difficulty selector
     names := memory.DIFFICULTY_NAMES
     layouts := memory.LAYOUTS
-    ui.draw_text_centered("Difficulty  (Left / Right)", themes.SCREEN_WIDTH / 2, 500, 20, raylib.Fade(theme.ink, 0.7))
+    ui.draw_text_centered("Difficulty  (Left / Right)", themes.SCREEN_WIDTH / 2, 512, 20, raylib.Fade(theme.ink, 0.7))
     seg_w: f32 = 150
     seg_x := (themes.SCREEN_WIDTH - 3 * seg_w - 2 * 12) / 2
     for level in memory.Difficulty {
         selected := difficulty^ == level
         color := selected ? theme.primary : raylib.ColorLerp(theme.primary, themes.WHITE, 0.55)
         label := raylib.TextFormat("%s  %d", names[level], layouts[level].rows * layouts[level].cols / 2)
-        if ui.button({seg_x, 530, seg_w, 48}, label, color, font_size = 22, selected = selected) {
+        if ui.button({seg_x, 542, seg_w, 48}, label, color, font_size = 22, selected = selected) {
             difficulty^ = level
         }
         seg_x += seg_w + 12