Initial commit

**Motivations:**
- Initialisation du versionning git pour le projet

**Root causes:**
- N/A (Nouveau projet)

**Correctifs:**
- N/A

**Evolutions:**
- Structure initiale du projet
- Ajout du .gitignore

**Pages affectées:**
- Tous les fichiers

web/js/grid-utils.js

@@ -0,0 +1,62 @@
+import { GameConfig } from "./config.js";
+
+/**
+ * @param {number} x
+ * @param {number} y
+ * @returns {string}
+ */
+export function cellKey(x, y) {
+  return `${x}_${y}`;
+}
+
+/**
+ * @param {number} plotLevel
+ * @returns {[number, number]}
+ */
+export function plotSizeFromLevel(plotLevel) {
+  const level = Math.max(1, Math.min(GameConfig.Plot.MaxLevel, plotLevel));
+  const extra = (level - 1) * GameConfig.Plot.ExpandByLevel;
+  return [
+    GameConfig.Plot.BaseWidth + extra,
+    GameConfig.Plot.BaseHeight + extra,
+  ];
+}
+
+/**
+ * @param {number} width
+ * @param {number} height
+ * @param {number} x
+ * @param {number} y
+ * @returns {boolean}
+ */
+export function withinBounds(width, height, x, y) {
+  return x >= 1 && y >= 1 && x <= width && y <= height;
+}
+
+/**
+ * Keys for a rectangular block (origin = top-left). All coordinates 1-based.
+ * @param {number} originX
+ * @param {number} originY
+ * @param {number} w
+ * @param {number} h
+ * @returns {string[]}
+ */
+export function getBlockKeys(originX, originY, w, h) {
+  const keys = [];
+  for (let dy = 0; dy < h; dy++) {
+    for (let dx = 0; dx < w; dx++) {
+      keys.push(cellKey(originX + dx, originY + dy));
+    }
+  }
+  return keys;
+}
+
+/**
+ * @param {string} key "x_y"
+ * @param {import("./types.js").Cell} cell
+ * @returns {boolean}
+ */
+export function isOriginCell(key, cell) {
+  if (cell === null || cell === undefined || cell.kind !== "animal") return false;
+  return cell.originKey === null || cell.originKey === undefined || cell.originKey === key;
+}