Add Windows installer packaging (Setup.exe + portable exe)

PyInstaller onedir/onefile specs, Inno Setup script, and GitHub Actions
workflow to produce JUC500-Setup-win64.exe and portable builds.

Co-authored-by: Cursor <cursoragent@cursor.com>

juc500-windows-onefile.spec

@@ -0,0 +1,65 @@
+# -*- mode: python ; coding: utf-8 -*-
+# Windows 64-bit 단일 EXE (포터블)
+from pathlib import Path
+
+from PyInstaller.utils.hooks import collect_submodules
+
+ROOT = Path(SPECPATH).resolve()
+STATIC = ROOT / "juc500_xfer" / "static"
+VENDOR_DLL = ROOT / "vendor" / "libusb-1.0.dll"
+
+hidden = collect_submodules("juc500_xfer")
+
+datas = []
+for f in STATIC.iterdir():
+    if f.is_file():
+        datas.append((str(f), "static"))
+        datas.append((str(f), "juc500_xfer/static"))
+
+binaries = []
+if VENDOR_DLL.is_file():
+    binaries.append((str(VENDOR_DLL), "."))
+
+a = Analysis(
+    [str(ROOT / "juc500_app.py")],
+    pathex=[str(ROOT)],
+    binaries=binaries,
+    datas=datas,
+    hiddenimports=hidden + [
+        "usb",
+        "usb.core",
+        "usb.util",
+        "usb.backend",
+        "usb.backend.libusb1",
+    ],
+    hookspath=[],
+    hooksconfig={},
+    runtime_hooks=[],
+    excludes=[],
+    noarchive=False,
+    optimize=0,
+)
+
+pyz = PYZ(a.pure)
+
+exe = EXE(
+    pyz,
+    a.scripts,
+    a.binaries,
+    a.datas,
+    [],
+    name="JUC500-portable",
+    debug=False,
+    bootloader_ignore_signals=False,
+    strip=False,
+    upx=False,
+    upx_exclude=[],
+    runtime_tmpdir=None,
+    console=True,
+    disable_windowed_traceback=False,
+    argv_emulation=False,
+    target_arch=None,
+    codesign_identity=None,
+    entitlements_file=None,
+    icon=None,
+)