Decorated functions made into cells keep the function name

### Describe the bug If I have a function that uses a variable defined in another cell in its body, the function definition (`@app.function`) will be converted into a cell (`@app.cell`). Normally, this will be a cell without a name (`def _(): ...`), but if the original function is decorated, the new cell will inherit the original name of the function. ### Environment <details> ``` marimo VS Code Extension Diagnostics ===================================== Language Server (LSP): UV Bin: Bundled (c:\Users\andrew\.vscode\extensions\marimo-team.vscode-marimo-0.13.3-win32-x64\bundled\libs\bin\uv.exe) UV: 0.11.3 (45da18ac3 2026-04-01) ✓ Using bundled marimo-lsp via uvx Python Extension: Interpreter: c:\Users\andrew\Code\project\code\.venv\Scripts\python.exe Version: 3.13.9.final.0 Environment: VirtualEnvironment (biaxtic) Python Language Server (ty): Status: running ✓ Version: 0.0.26 (940305127 2026-03-26) Binary: UvInstalled (c:\Users\andrew\AppData\Roaming\Code\User\globalStorage\marimo-team.vscode-marimo\libs\bin\ty.exe) Python: c:\Users\avg170002\Code\biaxial-bioreactor\code\.venv\Scripts\python.exe (3.13.9.final.0) Ruff Language Server: Status: running ✓ Version: 0.15.14 Binary: CompanionExtension/bundled (charliermarsh.ruff, c:\Users\avg170002\.vscode\extensions\charliermarsh.ruff-2026.44.0-win32-x64\bundled\libs\bin\ruff.exe) Extension Configuration: Version: 0.13.3 UV integration disabled: false System Information: Host: desktop IDE: Visual Studio Code IDE version: 1.121.0 Platform: win32 Architecture: x64 Node version: v22.22.1 Common Issues: 1. If notebooks won't open: - Check Python interpreter is selected - Ensure marimo is installed - Check 'marimo-lsp' output channel for errors 2. If features are missing: - Ensure marimo version is >= 0.23.3 - Try reloading the window ``` </details> ### Steps to reproduce Starter notebook: ```python import marimo __generated_with = "0.23.6" app = marimo.App() @app.function def deco(func): return func @app.cell def _(): x = 2 return @app.function @deco def foo(): return "Hello" @app.cell def _(): foo() return if __name__ == "__main__": app.run() ``` Edit `foo()` to include the external variable `x`, and it will become: ```python @app.cell def foo(x): # <-- Expected to be `def _(x):` @deco def foo(): return "Hello" * x return (foo,) ```