perf: let nodeps.js use the host's Vuetify instead of a second copy

[maartenbreddels]

nodeps.js (the bundle Solara loads) now uses the Vuetify of the host page instead of bundling a second copy, which cuts it from 354 KB to 18 KB gzip.

Problem

nodeps.js is meant for hosts that already have Vue and Vuetify, such as Solara.
It still bundled Vuetify's components, directives, and a copy of the Vuetify CSS scoped to .vuetify-styles.
That is 2.6 MB raw and 354 KB gzip that every Solara page downloads, for code and styles the page already has.
The page also ran two Vuetify instances: Solara's, and one for widgets that ipywidgets containers (Lumino) host.

Change

• VuetifyView.js gets its Vuetify plugin from createVuetifyPlugin() in the new vuetifyPlugin.js.
  For index.js and the labextension, that module is the same createVuetify(...) with styles as before, so Jupyter does not change.
• For both nodeps.js builds, webpack replaces ./vuetifyPlugin with nodepsVuetifyPlugin.js.
  It returns the host's global vuetifyPlugin, and throws a clear error when the host has none.
  It reads the global instead of the AMD module solara-vuetify-plugin, because Solara 1.23 to 1.60 run Vue 3 but do not define that module (it came in 1.61.0).
  When the host's Vuetify has an older major or minor version than the one ipyvuetify is built for, it logs a console warning that names the versions and says to upgrade Solara.
• VuetifyApp.js: the DatePicker wrapper resolves VDatePicker from the app it renders in (the host's Vuetify in nodeps.js, ipyvuetify's in Jupyter), instead of importing it.
• nodepsVuetifyView.js and plugins/nodepsVuetify.js were dead Vue 2 code, so I deleted them.
• All five AMD builds (extension.js, index.js, both nodeps.js, dist/index.js) now minify with webpack's default Terser settings plus wrap_func_args. Terser 5.43 stopped putting a function argument in parentheses by default. Without them, V8 compiles the AMD factory lazily on the main thread when require.js calls it. With them, V8 compiles it with the script, on a background thread when the script streams. The build adds the devDependency minimizer-webpack-plugin, the Terser plugin that webpack uses for its own default minimizer.
• CI: the build job fails when either nodeps.js (nbextension or js/dist) is over 250,000 bytes or contains v-data-table. That string is 394 times in the 3.0.0 copy and 0 times in the new one.
  The ui-test job does not check the installed nodeps.js again. CI installs the PR wheel by path, and overlay_css_test.py fails when an older nodeps.js replaces it.
• New overlay_css_test.py (Solara runner) loads a custom.css with .v-btn { text-transform: none; } and checks a Lumino-hosted button and a button in a menu overlay. It passes with this PR and fails with the 3.0.0 nodeps.js.
• New tests/ui/conftest.py: on the Solara runner, a test fails on a page error, or on a console message about an older host Vuetify or a component that did not resolve.

Sizes

file	before raw / gzip	after raw / gzip
nodeps.js	2,594,705 / 353,753	120,837 / 18,148
nodeps.js.map	4,802,166	349,951
index.js	3,722,133 / 473,677	3,726,227 / 474,471

Validation

• On the Solara runner (released Solara 1.64.0, released ipyvue 3.0.0), I ran each test once with the released 3.0.0 nodeps.js and once with the new one:

  • button_test.py: I made a darwin reference with 3.0.0; the new build matched it. I did not commit that reference.
  • new date_picker_test.py: clicking day 20 sets v_model to 2024-01-20. It passed with both builds.

• A Solara 1.64.0 app with a custom CSS rule .v-btn { text-transform: none; }, a Lumino-hosted v.Btn(color="primary"), a v-menu, and the dark theme, measured with Playwright:

  button	3.0.0	this PR
  main tree	none	none
  Lumino-hosted	uppercase	none
  menu activator and overlay	uppercase	none

  Background and text colors were the same in both builds, in light and dark mode.
  The page had 126 <style> elements with 3.0.0 and 8 with this PR. The console had no warnings or errors.

• Solara 1.60.3 (Vuetify 3.3.23) with released 3.0.0: the Lumino-hosted button and the date picker did not render (useId is not a function, Could not find injected date options).
  With this PR, the page renders and does not hang. The date picker stays empty, because Vuetify 3.3 has no VDatePicker, and the console shows the version warning.

• Wrapper: on a Solara 1.64 page with one ipyvuetify button at 4x CPU slowdown (Playwright Chromium, median of 5 loads per build), the nodeps.js factory call takes 5.0 ms instead of 15.3 ms. The main-thread compile inside it takes 1.5 ms instead of 11.0 ms.

Gaps

• I did not run the voila, jupyter_lab and jupyter_notebook runners locally; CI runs them. index.js grew by 4,094 bytes (794 gzip). 50 bytes come from the plugin module, and the rest from the wrap_func_args parentheses.
• Hosts other than Solara that load nodeps.js (for example py.cafe) are not checked. They must set the global vuetifyPlugin and have Vuetify CSS on the page.
• With Solara before 1.61 (Vuetify 3.3), components that Vuetify 3.3 lacks do not render. Before this PR, those versions failed with errors.
• When Solara runs without Vuetify (its planned -vuetify mode), AMD vuetify must resolve through a loader that also sets window.vuetifyPlugin first. That is the Solara PR's job.

Visible changes in full (need Maarten's OK)

• App CSS now beats Vuetify rules of equal specificity inside overlays and Lumino-hosted views, as it already did in the main tree. Before, the scoped Vuetify copy loaded after custom.css and won there (see the table above).
• Lumino-hosted ipyvuetify views now use Solara's Vuetify instance and theme instead of their own instance. I saw no color difference in light or dark mode, but there is now one writer to vuetify-theme-stylesheet instead of two.

Review

Three reviewers checked this change together with the ipyvue change, each from one angle: template compile semantics, host compatibility (JupyterLab, notebook, Voila, old and new Solara), and build and packaging.
They found no problems in this repository.

This PR is part of the Solara page-load work; the Solara PR that sets the host vuetifyPlugin for this bundle is widgetti/solara#1235.

🤖 Generated with Claude Code

[maartenbreddels]

Replaced by #350, which gets the same nodeps.js win (354 to 18 KB gzip) with a much smaller diff: 5 files instead of 13, no new tests, CI checks or unrelated build changes.