fix: 修复GUI启动设置卡片pack/grid混用导致的崩溃

- 启动设置卡片改用统一pack布局
- 修复Windows上启动即崩溃的 TclError 问题

launcher.py

@@ -686,20 +686,24 @@ class MeowLauncherApp:
                         command=self.refresh_versions).pack(anchor="w", pady=(6, 0))
 
         cfg = self._card(self.tab_launch, "启动设置")
-        ttk.Label(cfg, text="最大内存 (MB):", style="Card.TLabel").grid(row=0, column=0, sticky="w", pady=3)
+        row = ttk.Frame(cfg, style="Card.TFrame")
+        row.pack(fill="x", pady=3)
+        ttk.Label(row, text="最大内存 (MB):", style="Card.TLabel").pack(side="left")
         self.mem_var = tk.StringVar(value="2048")
-        ttk.Entry(cfg, textvariable=self.mem_var, width=10).grid(row=0, column=1, sticky="w", pady=3)
-        ttk.Label(cfg, text="Java 路径 (留空自动检测):", style="Card.TLabel").grid(row=1, column=0, sticky="w", pady=3)
+        ttk.Entry(row, textvariable=self.mem_var, width=10).pack(side="left", padx=8)
+
         row = ttk.Frame(cfg, style="Card.TFrame")
-        row.grid(row=1, column=1, sticky="w", pady=3)
+        row.pack(fill="x", pady=3)
+        ttk.Label(row, text="Java 路径 (留空自动检测):", style="Card.TLabel").pack(side="left")
         self.java_var = tk.StringVar()
-        ttk.Entry(row, textvariable=self.java_var, width=16).pack(side="left")
+        ttk.Entry(row, textvariable=self.java_var, width=16).pack(side="left", padx=8)
         ttk.Button(row, text="浏览", command=self._pick_java).pack(side="left", padx=4)
-        ttk.Label(cfg, text="游戏目录:", style="Card.TLabel").grid(row=2, column=0, sticky="w", pady=3)
+
         row = ttk.Frame(cfg, style="Card.TFrame")
-        row.grid(row=2, column=1, sticky="w", pady=3)
+        row.pack(fill="x", pady=3)
+        ttk.Label(row, text="游戏目录:", style="Card.TLabel").pack(side="left")
         self.dir_var = tk.StringVar(value=str(Path.home() / ".minecraft"))
-        ttk.Entry(row, textvariable=self.dir_var, width=16).pack(side="left")
+        ttk.Entry(row, textvariable=self.dir_var, width=16).pack(side="left", padx=8)
         ttk.Button(row, text="浏览", command=self._pick_dir).pack(side="left", padx=4)
 
         log_card = self._card(self.tab_launch, "日志")