fix: mobile entry click and add fullscreen button

- Delay virtual controls creation until after game starts (ctrl overlay
  was intercepting title screen touches)
- Add touchstart handler on game container for mobile entry
- Add fullscreen button overlay in top-right corner
- Hide title text after game starts

source/main.js

@@ -123,12 +123,32 @@ game_load = async () => {
 	requestAnimationFrame(run_frame);
 
 	f.onclick = () => g.requestFullscreen();
-	g.onclick = () => {
-		if (!is_touch) {
+
+	// Mobile: fullscreen button overlay in top-right
+	if (is_touch) {
+		let fs_btn = document.createElement('button');
+		fs_btn.id = 'btn-fs';
+		fs_btn.textContent = '⛶';
+		fs_btn.onclick = () => g.requestFullscreen();
+		document.getElementById('g').appendChild(fs_btn);
+	}
+
+	// Game start handler
+	let start_game = () => {
+		// Remove the entry handler so it only fires once
+		g.onclick = null;
+		if (g._touch_entry) {
+			g.removeEventListener('touchstart', g._touch_entry);
+			g._touch_entry = null;
+		}
+		if (is_touch) {
+			// Create virtual controls now that game is starting
+			create_touch_controls();
+		} else {
 			g.onclick = () => c.requestPointerLock();
 			g.onclick();
 		}
-		
+
 		audio_init();
 
 		// Generate sounds
@@ -157,6 +177,13 @@ game_load = async () => {
 		game_init(0);
 		run_frame = game_run;
 	};
+
+	// Wire up game start: click for desktop, touch for mobile
+	g.onclick = start_game;
+	if (is_touch) {
+		g._touch_entry = (e) => { e.preventDefault(); start_game(); };
+		g.addEventListener('touchstart', g._touch_entry, {passive: false});
+	}
 },
 
 run_frame = (time_now) => {