Lint: fix errors and remove unused variables

**Motivations:**
- Ensure lint config is not degraded and fix all lint errors for pousse workflow.

**Root causes:**
- Unused variables kept with _ prefix instead of removed (_row, _questReward, _i).
- getAnimalBlockOrigin had 5 parameters (max 4).
- use of continue statement (no-continue rule).

**Correctifs:**
- ESLint config verified; no eslint-disable in codebase.
- Removed unused variable _row (biome-rules); removed dead function _questReward (quests); removed unused map param _i (state.js).
- getAnimalBlockOrigin refactored to 4 params (pos object instead of x, y).
- Replaced continue with if (cell) block in normalizeLoadedCells (state.js).
- JSDoc param names aligned with _height, _y (biome-rules).

**Evolutions:**
- (none)

**Pages affectées:**
- web/js/biome-rules.js
- web/js/quests.js
- web/js/state.js
- web/js/placement.js

web/js/ui-helpers.js

@@ -0,0 +1,36 @@
+/**
+ * @param {string} labelContent
+ * @param {string} tooltipText
+ * @returns {HTMLElement}
+ */
+export function makeHelpWrap(labelContent, tooltipText) {
+  const wrap = document.createElement("div");
+  wrap.className = "help-wrap";
+  const label = document.createElement("span");
+  label.textContent = labelContent;
+  const icon = document.createElement("span");
+  icon.className = "help-icon";
+  icon.setAttribute("aria-label", "Aide");
+  icon.textContent = "?";
+  const bubble = document.createElement("div");
+  bubble.className = "tooltip-bubble";
+  bubble.textContent = tooltipText;
+  wrap.append(label, icon, bubble);
+  return wrap;
+}
+
+/**
+ * @param {HTMLElement} parent
+ * @param {string} titleText
+ * @param {string} helpText
+ * @returns {void}
+ */
+export function addSectionTitle(parent, titleText, helpText) {
+  const section = document.createElement("div");
+  section.className = "section-with-help";
+  const h2 = document.createElement("h2");
+  h2.textContent = titleText;
+  section.appendChild(h2);
+  section.appendChild(makeHelpWrap("", helpText));
+  parent.appendChild(section);
+}