Add four animated KonoSuba ESPHome pages

Megumin's daily explosion, the Adventurers' Guild quest board (agenda,
weather, solar), Megumin's adventurer card and a party battle against a
giant toad with a live-data battle log. Original 1-bit pixel art lives in
tools/konosuba_sprites.py, which generates konosuba_sprites.h and can
render a preview PNG.

Home data and drawing helpers shared by the themed pages move to
el512_pages.h; the display gains dither_mask() for a dissolve-in intro.

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

components/el512/konosuba.h

@@ -0,0 +1,41 @@
+// KonoSuba-themed animated pages for the ESPHome display: Megumin's daily
+// explosion, the Adventurers' Guild quest board, Megumin's adventurer card and
+// a party battle against a giant toad. Fan art: the pixel art
+// (konosuba_sprites.h, from tools/konosuba_sprites.py) and all texts are
+// original; no material from the series is used.
+//
+// Each function draws a whole page. Call it from a page lambda and list that
+// page under animated_pages; the animation clock is the display's page_age_ms().
+#pragma once
+
+#include "el512_pages.h"
+#include "esphome/components/display/display.h"
+#include "esphome/core/time.h"
+
+namespace esphome::el512 {
+
+class EL512Display;
+
+namespace konosuba {
+
+struct Fonts {
+  display::BaseFont *title{nullptr};    // fantasy serif headers (Cinzel)
+  display::BaseFont *big{nullptr};      // "EXPLOSION!" (Cinzel Decorative)
+  display::BaseFont *text{nullptr};     // rounded body text (Nunito)
+  display::BaseFont *pixel{nullptr};    // 8 px pixel font (Press Start 2P)
+  display::BaseFont *pixel_l{nullptr};  // 16 px pixel font
+  display::BaseFont *jp{nullptr};       // a few Japanese words (Noto Sans JP)
+  display::BaseFont *jp_big{nullptr};   // 爆裂魔法 (Dela Gothic One)
+  display::BaseFont *weather{nullptr};  // weather icons (Material Design Icons)
+};
+
+void explosion(EL512Display &it, const Fonts &f, const HomeData &d, ESPTime now);
+void guild_board(EL512Display &it, const Fonts &f, const HomeData &d, ESPTime now);
+void adventurer_card(EL512Display &it, const Fonts &f, const HomeData &d, ESPTime now);
+void party_battle(EL512Display &it, const Fonts &f, const HomeData &d);
+
+// Explosions cast on the Explosion page since midnight.
+uint32_t explosions_today();
+
+}  // namespace konosuba
+}  // namespace esphome::el512