Document packaging with Nuitka

[falkoschindler]

Motivation

NiceGUI's nicegui/ui.py resolves submodules lazily via a module-level __getattr__ (PEP 562). Nuitka's static analyzer can't trace importlib.import_module(module_path, ...) when module_path comes from a dict lookup, so submodules like nicegui.ui_run, nicegui.functions.style, and most nicegui.elements.* get pruned from Nuitka builds. PyInstaller side-steps this because nicegui-pack already passes --add-data <nicegui dir>.

Users have been hitting this for a while:

• When using nuitka for packaging, lazy imports will throw a ModuleNotFoundError #6009 — ModuleNotFoundError: No module named 'nicegui.ui_run' after Nuitka build
• Describe how to package executable with Nuitka #2165 — long-standing request for documented Nuitka packaging instructions

Both are unblocked by passing --include-package=nicegui --include-package-data=nicegui. This PR documents that.

Implementation

Adds a "Packaging with Nuitka" section to the deployment docs, between the existing PyInstaller block and the generic "Packaging with Native Mode" notes. Same structure as the PyInstaller demo: intro paragraph with flag rationale, 2-column python_window/bash_window pair with a working example, and a tips list covering --standalone vs --onefile, optional packages with their own data files, native-mode flags per platform, and build-time / cache notes.

The recommended invocation was verified locally — clean venv on Python 3.11.7 with Nuitka 4.0.8 + this branch's nicegui produced a 191 MB onefile binary that successfully resolves all lazy imports (ui.label, ui.add_css) used in #6009's repro.

Progress

• Title starts with a verb
• Implementation complete
• Not a security issue
• Pytests not necessary
• Documentation added
• No breaking changes

[evnchn]

@falkoschindler looks correct. Do you want to YOLO this or want Windows testing on my side?

[falkoschindler]

@evnchn Let's YOLO and improve on demand.

[evnchn]

YOLO it is, then