feat: migrate ORM base to sqlmodel-ext, add file viewers and WOPI integration

- Migrate SQLModel base classes, mixins, and database management to
  external sqlmodel-ext package; remove sqlmodels/base/, sqlmodels/mixin/,
  and sqlmodels/database.py
- Add file viewer/editor system with WOPI protocol support for
  collaborative editing (OnlyOffice, Collabora)
- Add enterprise edition license verification module (ee/)
- Add Dockerfile multi-stage build with Cython compilation support
- Add new dependencies: sqlmodel-ext, cryptography, whatthepatch

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

setup_cython.py

@@ -0,0 +1,91 @@
+"""
+Cython 编译脚本 — 将 ee/ 下的纯逻辑文件编译为 .so
+
+用法：
+    uv run --extra build python setup_cython.py build_ext --inplace
+
+编译规则：
+    - 跳过 __init__.py（Python 包发现需要）
+    - 只编译 .py 文件（纯函数 / 服务逻辑）
+
+编译后清理（Pro Docker 构建用）：
+    uv run --extra build python setup_cython.py clean_artifacts
+"""
+import shutil
+import sys
+from pathlib import Path
+
+EE_DIR = Path("ee")
+
+# 跳过 __init__.py —— 包发现需要原始 .py
+SKIP_NAMES = {"__init__.py"}
+
+
+def _collect_modules() -> list[str]:
+    """收集 ee/ 下需要编译的 .py 文件路径（点分模块名）。"""
+    modules: list[str] = []
+    for py_file in EE_DIR.rglob("*.py"):
+        if py_file.name in SKIP_NAMES:
+            continue
+        # ee/license.py → ee.license
+        module = str(py_file.with_suffix("")).replace("\\", "/").replace("/", ".")
+        modules.append(module)
+    return modules
+
+
+def clean_artifacts() -> None:
+    """删除已编译的 .py 源码、.c 中间文件和 build/ 目录。"""
+    for py_file in EE_DIR.rglob("*.py"):
+        if py_file.name in SKIP_NAMES:
+            continue
+        # 只删除有对应 .so / .pyd 的源文件
+        parent = py_file.parent
+        stem = py_file.stem
+        has_compiled = (
+            any(parent.glob(f"{stem}*.so")) or
+            any(parent.glob(f"{stem}*.pyd"))
+        )
+        if has_compiled:
+            py_file.unlink()
+            print(f"已删除源码: {py_file}")
+
+    # 删除 .c 中间文件
+    for c_file in EE_DIR.rglob("*.c"):
+        c_file.unlink()
+        print(f"已删除中间文件: {c_file}")
+
+    # 删除 build/ 目录
+    build_dir = Path("build")
+    if build_dir.exists():
+        shutil.rmtree(build_dir)
+        print(f"已删除: {build_dir}/")
+
+
+if __name__ == "__main__":
+    if len(sys.argv) > 1 and sys.argv[1] == "clean_artifacts":
+        clean_artifacts()
+        sys.exit(0)
+
+    # 动态导入（仅在编译时需要）
+    from Cython.Build import cythonize
+    from setuptools import Extension, setup
+
+    modules = _collect_modules()
+    if not modules:
+        print("未找到需要编译的模块")
+        sys.exit(0)
+
+    print(f"即将编译以下模块: {modules}")
+
+    extensions = [
+        Extension(mod, [mod.replace(".", "/") + ".py"])
+        for mod in modules
+    ]
+
+    setup(
+        name="disknext-ee",
+        ext_modules=cythonize(
+            extensions,
+            compiler_directives={'language_level': "3"},
+        ),
+    )