chore(controller): three-player-controller als Ordner statt Submodul

Das Submodul zeigte auf GitHub, der eingetragene Stand 028c652 lag aber nur
lokal vor: GitHub-Master ac39682 plus Showcase mit Figuren und launch.json.
Frische Klone konnten den Controller deshalb nicht laden. Jetzt liegt dieser
Stand als normaler Ordner im Repo, ohne Verweis auf GitHub.

dist/ und node_modules/ im Controller bleiben ignoriert und werden wie bisher
lokal gebaut.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

three-player-controller/example/shooting/ui/HUD.js

@@ -0,0 +1,65 @@
+// HUD：准星 + 武器选择栏 + 弹药显示
+// 不依赖任何 Three.js 对象，只操作 DOM
+export class HUD {
+    constructor(weaponSlots) {
+        this._slots = weaponSlots; // [{ key, mode, label }]
+
+        this._crosshair = document.getElementById("crosshair");
+        this._weaponHud = document.getElementById("weapon-hud");
+        this._ammoHud = document.getElementById("ammo-hud");
+        this._ammoCurrent = document.getElementById("ammo-current-val");
+        this._ammoTotal = document.getElementById("ammo-total-val");
+        this._hitTimer = null;
+    }
+
+    // ==================== 初始化 ====================
+
+    build() {
+        this._weaponHud.innerHTML = "";
+        for (let i = this._slots.length - 1; i >= 0; i--) {
+            const slot = this._slots[i];
+            const el = document.createElement("div");
+            el.className = "weapon-slot";
+            el.dataset.mode = slot.mode;
+            el.innerHTML = `<span class="slot-key">${slot.key}</span><span class="slot-name">${slot.label}</span>`;
+            this._weaponHud.appendChild(el);
+        }
+    }
+
+    // ==================== 武器槽 ====================
+
+    update(currentMode) {
+        this._weaponHud.querySelectorAll(".weapon-slot").forEach((el) => {
+            el.classList.toggle("active", el.dataset.mode === currentMode);
+        });
+    }
+
+    // ==================== 弹药 ====================
+
+    updateAmmo(current, max) {
+        if (this._ammoCurrent) this._ammoCurrent.textContent = current;
+        if (this._ammoTotal) this._ammoTotal.textContent = max;
+    }
+
+    showAmmo() {
+        if (this._ammoHud) this._ammoHud.style.display = "flex";
+    }
+
+    hideAmmo() {
+        if (this._ammoHud) this._ammoHud.style.display = "none";
+    }
+
+    // ==================== 准星 ====================
+
+    showCrosshair() { this._crosshair.style.display = "block"; }
+    hideCrosshair() { this._crosshair.style.display = "none"; }
+
+    flashHit() {
+        if (!this._crosshair) return;
+        if (this._hitTimer) clearTimeout(this._hitTimer);
+        this._crosshair.style.backgroundColor = "red";
+        this._hitTimer = setTimeout(() => {
+            this._crosshair.style.backgroundColor = "";
+        }, 100);
+    }
+}