Track longest chain records per scene

src/main.js

@@ -138,6 +138,7 @@
   let spawnCount = 0;
   let score = 0;
   let highScore = 0;
+  let longestChainRecord = 0;
   let clearedCount = 0;
   let clearedByColor = {};
   let gameOver = false;
@@ -148,6 +149,7 @@
   let dragConstraint = null;
 
   const makeStorageKey = (sceneId) => `physilinks-highscore-${sceneId}`;
+  const makeChainKey = (sceneId) => `physilinks-longestchain-${sceneId}`;
 
   const loadHighScore = (sceneId) => {
     try {
@@ -159,6 +161,16 @@
     }
   };
 
+  const loadLongestChain = (sceneId) => {
+    try {
+      const raw = localStorage.getItem(makeChainKey(sceneId));
+      const parsed = parseInt(raw, 10);
+      return Number.isFinite(parsed) ? parsed : 0;
+    } catch (err) {
+      return 0;
+    }
+  };
+
   const saveHighScore = () => {
     try {
       localStorage.setItem(makeStorageKey(currentScene.id), String(highScore));
@@ -167,6 +179,17 @@
     }
   };
 
+  const saveLongestChain = () => {
+    try {
+      localStorage.setItem(
+        makeChainKey(currentScene.id),
+        String(longestChainRecord),
+      );
+    } catch (err) {
+      // ignore write failures
+    }
+  };
+
   const applyScene = (sceneId) => {
     const next = getSceneById(sceneId) || scenes[0];
     if (!next) return;
@@ -215,6 +238,7 @@
     levelWon = false;
     clearedByColor = {};
     highScore = loadHighScore(next.id);
+    longestChainRecord = loadLongestChain(next.id);
     rebuildSceneBodies();
     buildLegend();
     restartGame();
@@ -623,6 +647,15 @@
   const finishChain = (releasePoint) => {
     if (!chain.active || gameOver || isPaused) return;
     if (chain.bodies.length >= config.minChain) {
+      const chainLength = chain.bodies.length;
+      if (chainLength > longestChainRecord) {
+        longestChainRecord = chainLength;
+        saveLongestChain();
+        ui.showFloatingMessage(`New chain record: ${chainLength}`, {
+          durationMs: 3600,
+          position: config.messages.position,
+        });
+      }
       const baseGain = 10 * Math.pow(chain.bodies.length, 2);
       const negativeColors = (
         currentScene?.config?.negativeScoreColors || []