feat(tetris-attack): add character background sprites

Add new background images for Klaxon, Steve, and Victor characters
with 5 animation states each (r1-r5).

fix(civilization): resolve hotkey capture in city naming modal

Store hotkey list in this.hotkeyList to properly clear and restore
keyboard captures when opening/closing the city name input modal.
Previously, gameplay hotkeys prevented typing in the input field.

src/games/civilization/CivilizationGame.js

@@ -84,7 +84,8 @@ export default class CivilizationGame extends Phaser.Scene {
     this.setupRoot = null;
     this.toasts = [];
 
-    this.keys = this.input.keyboard.addKeys('UP,DOWN,LEFT,RIGHT,Q,E,Z,C,W,A,S,D,B,F,G,I,M,N,O,R,T,SPACE,ENTER');
+    this.hotkeyList = 'UP,DOWN,LEFT,RIGHT,Q,E,Z,C,W,A,S,D,B,F,G,I,M,N,O,R,T,SPACE,ENTER';
+    this.keys = this.input.keyboard.addKeys(this.hotkeyList);
     this.escHandler = () => this.onEscape();
     this.input.keyboard.on('keydown-ESC', this.escHandler);
     this.events.once('shutdown', () => {
@@ -966,6 +967,9 @@ export default class CivilizationGame extends Phaser.Scene {
 
   promptCityName(defaultName, onConfirm) {
     this.modalOpen = true;
+    // Gameplay hotkeys capture (preventDefault) these keys at the window level,
+    // which blocks the browser from typing them into the name field below.
+    this.input.keyboard.clearCaptures();
     const cx = GAME_WIDTH / 2;
     const cy = GAME_HEIGHT / 2;
     const root = this.add.container(0, 0).setDepth(D.modal);
@@ -985,7 +989,10 @@ export default class CivilizationGame extends Phaser.Scene {
     input.focus();
     input.el.select();
 
-    const close = () => { input.destroy(); root.destroy(true); this.modalOpen = false; };
+    const close = () => {
+      input.destroy(); root.destroy(true); this.modalOpen = false;
+      this.input.keyboard.addCapture(this.hotkeyList);
+    };
     const confirm = () => {
       const name = input.value.trim() || defaultName;
       close();