Add debug province highlighting feature

Adds a debug panel that allows typing province names to highlight them on the map with a flashing yellow animation. Only visible when debug mode is enabled.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

ai_animation/src/debug/provinceHighlight.ts

@@ -0,0 +1,121 @@
+import { gameState } from "../gameState";
+import { ProvinceENUM } from "../types/map";
+import { MeshBasicMaterial } from "three";
+
+interface FlashAnimation {
+  mesh: THREE.Mesh;
+  originalColor: number;
+  startTime: number;
+  duration: number;
+}
+
+let currentFlashAnimation: FlashAnimation | null = null;
+
+/**
+ * Highlights a province on the map with a flashing animation
+ * @param provinceName - The name of the province to highlight (e.g., "PAR", "LON", "BER")
+ */
+export function highlightProvince(provinceName: string): void {
+  // Stop any existing animation
+  if (currentFlashAnimation) {
+    stopCurrentFlash();
+  }
+
+  // Normalize the province name to uppercase
+  const normalizedName = provinceName.toUpperCase().trim();
+  
+  // Check if it's a valid province
+  if (!Object.values(ProvinceENUM).includes(normalizedName as ProvinceENUM)) {
+    console.warn(`Province "${normalizedName}" not found. Valid provinces are:`, Object.values(ProvinceENUM));
+    return;
+  }
+
+  // Find the province in the board state
+  const province = gameState.boardState.provinces[normalizedName];
+  if (!province || !province.mesh) {
+    console.warn(`Province "${normalizedName}" mesh not found on the map`);
+    return;
+  }
+
+  // Get the mesh material
+  const material = province.mesh.material as MeshBasicMaterial;
+  const originalColor = material.color.getHex();
+
+  // Start the flash animation
+  currentFlashAnimation = {
+    mesh: province.mesh,
+    originalColor,
+    startTime: Date.now(),
+    duration: 2000 // 2 seconds
+  };
+
+  console.log(`Highlighting province: ${normalizedName}`);
+  
+  // Start the animation loop
+  animateFlash();
+}
+
+/**
+ * Animates the flashing effect
+ */
+function animateFlash(): void {
+  if (!currentFlashAnimation) return;
+
+  const elapsed = Date.now() - currentFlashAnimation.startTime;
+  const progress = elapsed / currentFlashAnimation.duration;
+
+  if (progress >= 1) {
+    // Animation complete, restore original color
+    stopCurrentFlash();
+    return;
+  }
+
+  // Calculate flash intensity using sine wave for smooth pulsing
+  const flashIntensity = Math.sin(elapsed * 0.01) * 0.5 + 0.5; // 0 to 1
+  
+  // Interpolate between original color and bright yellow
+  const material = currentFlashAnimation.mesh.material as MeshBasicMaterial;
+  const originalColor = currentFlashAnimation.originalColor;
+  
+  // Extract RGB components from original color
+  const originalR = (originalColor >> 16) & 255;
+  const originalG = (originalColor >> 8) & 255;
+  const originalB = originalColor & 255;
+  
+  // Flash to a bright yellow (255, 255, 0)
+  const flashR = 255;
+  const flashG = 255;
+  const flashB = 0;
+  
+  // Interpolate between original and flash colors
+  const r = Math.round(originalR + (flashR - originalR) * flashIntensity);
+  const g = Math.round(originalG + (flashG - originalG) * flashIntensity);
+  const b = Math.round(originalB + (flashB - originalB) * flashIntensity);
+  
+  // Set the new color
+  const newColor = (r << 16) | (g << 8) | b;
+  material.color.setHex(newColor);
+
+  // Continue animation
+  requestAnimationFrame(animateFlash);
+}
+
+/**
+ * Stops the current flash animation and restores the original color
+ */
+function stopCurrentFlash(): void {
+  if (!currentFlashAnimation) return;
+
+  // Restore original color
+  const material = currentFlashAnimation.mesh.material as MeshBasicMaterial;
+  material.color.setHex(currentFlashAnimation.originalColor);
+  
+  currentFlashAnimation = null;
+}
+
+/**
+ * Gets a list of all available province names
+ */
+export function getAvailableProvinces(): string[] {
+  return Object.values(ProvinceENUM);
+}