Add screen fade-in and card deal-in animations

Cards slide in one after another when a game starts and can't be picked
until they have landed.

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

src/memory/memory.odin

@@ -106,6 +106,7 @@ deal :: proc(deck_id: decks.Deck_Id, game_difficulty: Difficulty) {
     start_x := (themes.SCREEN_WIDTH - total_w) / 2
     start_y := themes.GRID_TOP + (themes.SCREEN_HEIGHT - 16 - themes.GRID_TOP - total_h) / 2
     for &c, i in active_cards() {
+        card.start_deal(&c, i)
         c.rect = {
             start_x + f32(i % layout.cols) * step_x,
             start_y + f32(i / layout.cols) * step_y,
@@ -134,6 +135,11 @@ unload :: proc() {
     for &c in cards { card.unload_face(&c) }
 }
 
+// Whether the player can click or press on card i right now (it must have finished being dealt)
+can_interact :: proc(i: int) -> bool {
+    return can_pick(i) && cards[i].deal_t == 0
+}
+
 can_pick :: proc(i: int) -> bool {
     if i < 0 || i >= card_count { return false }
     c := &cards[i]
@@ -190,7 +196,7 @@ handle_keyboard :: proc() {
     }
     if raylib.IsKeyPressed(.ENTER) || raylib.IsKeyPressed(.SPACE) {
         keyboard_active = true
-        select_card(focus)
+        if can_interact(focus) { select_card(focus) }
     }
 }
 
@@ -236,7 +242,7 @@ update :: proc(dt: f32) {
         elapsed += dt
         if raylib.IsMouseButtonPressed(.LEFT) {
             for &c, i in active_cards() {
-                if card.is_hovered(&c) && select_card(i) {
+                if card.is_hovered(&c) && can_interact(i) && select_card(i) {
                     break
                 }
             }
@@ -271,7 +277,7 @@ draw :: proc() -> themes.Screen {
     }
 
     for &c, i in active_cards() {
-        card.draw(&c, theme, can_pick(i), focused = keyboard_active && i == focus && state != .OVER)
+        card.draw(&c, theme, can_interact(i), focused = keyboard_active && i == focus && state != .OVER && c.deal_t == 0)
     }
 
     if state == .OVER {