Translate plugin content and labels in each app language (#7478)

* feat(website): serve paseo.sh in Simplified Chinese

Every page of the website now has a Simplified Chinese version under
/zh-CN: the interface, docs, blog posts, comparison pages, legal pages,
all changelog releases and the homepage mockup. English URLs are unchanged.

The URL alone decides the language. There is no browser-language redirect
and no stored preference, because either would have to redirect the
unprefixed English URLs that people share and search engines index.
Internal links carry the page's language instead, and hreflang alternates
point Chinese search results at /zh-CN.

Translated headings pin the English anchor with {#id}, so section links
work in both languages. content-translations.test.ts fails when a page
has no translation or a translation's headings drift from the English.
Changelog releases and plugin listings without a translation render
whole in English under a notice, so a release never waits on one.

Plugin manifests and the registry gain optional translations and
OVERVIEW.zh-CN.md fields; older clients and registries ignore them.

* feat(website): replace the native language select with an EN/ZH menu

The header showed an OS-native select whose popup did not match the site.
The trigger now shows the language abbreviated (EN, ZH) and opens a menu in
the app's dropdown style that names each language in itself, with its name
in the page language underneath. Rows are real links to the same page in
that language; arrows, Escape, outside presses and taps behave as a menu
button, and the menu keeps itself on screen when a narrow header pushes the
trigger toward an edge.

Also drops the stray space after the full-width comma in the Chinese
homepage subtitle.

* docs(website): translate main's new docs and 0.12.0 release notes

Main added Keep run workspaces to the schedules docs, rewrote plugin icons
around inline SVG, and promoted 0.12.0 with new entries. Bring the Chinese
pages and changelog in line so no section falls back to English.

* fix(server): leave plugin listing translations to the registry

The daemon rejected manifests whose translations the registry would refuse,
so a plugin main installs could fail to load here. Paseo never reads
translations; the registry validates them at publish. Docs now say which
checks are automated at publish and which are human review.

* docs(plugins): describe the registry's final overview translation discovery

* style(server): format manifest test

* feat(plugins): translate plugin UI in each app language

Keep translation resources and subscriptions inside each installation. Resolve host labels against the presentation locale so live language changes preserve mounted drafts and RPC state. Existing descriptor types retain string defaults for source compatibility.

* test(plugins): dismiss developer chrome in second translation client

* test(app): measure sidebar rows one at a time

After a reload the developer error toast appears while expectVerticalOrder
measures every row at once. Each concurrent boundingBox runs the toast
locator handler, and only one of them resumes, so the poll timed out on
every attempt since #7424. Measuring sequentially keeps one action in flight.

* test(app): return sidebar row measuring to main

#7480 hides the developer toast instead of running a locator handler, so
measuring the rows concurrently no longer races it. Reverts 41ac23016.

* test(app): wait for the compact shell before opening compact Changes

The shell survives the breakpoint, so right after the resize the wide
Explorer could still be visible: the test skipped the Explorer toggle and
the tab then disappeared, or toggled at the wrong time. Wait for the
compact-shell marker, as the composer helpers do since #7424.

* docs(website): translate main's plugin file panel docs

docs/plugins.md

@@ -86,6 +86,12 @@ plugin before compiling and starting from disk. A failed reload stays failed; Pa
 the old code. Use `enable`, `disable`, and `remove` to manage one plugin. Removing a directory source
 never deletes it. The global `pluginsEnabled` switch remains available.
 
+## Client translations
+
+Plugin runtime translations follow the connected app, so never send a daemon locale through RPCs or add plugin resources to the app catalog. The installation owns the translation engine; native portal bridges must carry it alongside RPC and client-state contexts. Keep host label resolution at presentation time so language changes preserve the installation lifetime.
+
+The author contract is in [runtime translations](../public-docs/plugins/reference.md#runtime-translations).
+
 ## Built-in plugins
 
 Built-in plugins ship from `plugins/<id>/`, with `paseo-plugin.json`, `index.server.ts`,