Cut duplicated and speculative code across the package

An over-engineering audit of the whole tree, applied in five reviewed
batches. Behaviour stays the same except where UPGRADE.md says otherwise.

PHP: the showcase and error-page stylesheets are prebuilt into
resources/dist by bin/stylesheets.mjs, through Vite's own postcss-import
(first occurrence kept, the order an application's build gives), instead
of Stylesheets::bundle() inlining imports on every request; only the
import walk DesignGuard needs stays. SchemeStylesheet::withProfiles()
replaces three copies of the scheme-plus-profiles loop, material:scheme
leaves spec and contrast checks to the node script that already made
them, and the error page's scheme cache, the hashed view namespace, the
translations path with no lang/ folder and DesignGuard's 1.x-name hints
are gone.

JS: the androidx shape port progress.js and both bin scripts each carried
lives once in resources/js/shapes.js (the generated SVGs are unchanged);
util.js holds ringIndex(), ms(), reopenGuard() and remember(), which
were written out several times; listeners are released through
AbortController; tooltip.js's hoverPopover() serves the rich tooltip too.

CSS: every rule for an element inside the navigation rail queries
`--md-navigation-rail-value` instead of repeating the seven collapsed
conditions under five media branches; badge, alert, progress, slider and
button read one non-inheriting colour-role table (components/color.css);
the dialog chrome, the submenu's popover chrome, the chip's state layer
and touch target, and the visually-hidden inputs use the shared rules
they copied; foundation/tokens.css is folded into foundation.css.

Views: Support\Field and Support\Link replace the error-key, bound-value
and link-attribute blocks copied into the fields and link components;
the timepicker period group, the menu filter and the showcase head are
partials; the datepicker's steppers and entry fields are loops; component
docblocks no longer restate SKILL.md.

Tests and tooling: one dataset-driven ComponentStylesheetsTest replaces
four per-group files, DesignGuardTest and the layout-component tests use
datasets, browser tests share one ready() helper, CSS parsing lives in
ComponentStylesheet alone. docs/audits and the finding IDs citing it are
removed, as are pestphp/pest-plugin-laravel, the unused composer scripts
and check:font; the lint job runs in the feature job, which now installs
node packages so the prebuilt-stylesheet staleness test runs in CI.

Feature suite 1177 passed, Chrome browser suite 299 passed.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

resources/css/components/section-nav.css

@@ -2,8 +2,8 @@
  * <x-section-nav>: the navigation inside one area of an application — M3's secondary tabs from
  * `medium` (600px), five or more of them the scrollable tab bar M3's own accessibility page
  * blesses rather than a grid that would break the tab bar's divider and strand the upper rows'
- * indicators against nothing (docs/audits/m3-alignment/navigation.md N-16); below `medium`, where a
- * row of them never fits, a button naming the current section opens the same list as a menu.
+ * indicators against nothing; below `medium`, where a row of them never fits, a button naming the
+ * current section opens the same list as a menu.
  *
  *   [data-md-section-nav]                min-inline-size: 0
  *     [data-md-section-nav-picker]       hidden from medium
@@ -14,7 +14,7 @@
  *
  * Reuses `<x-tabs>`'s own hooks and stylesheet rather than a tab bar of its own: a link marked
  * `aria-current="page"` takes the same active indicator and colour tabs.css already draws for
- * `aria-selected="true"` (N-21), so nothing here repeats a rule tabs.css owns; the only addition is
+ * `aria-selected="true"`, so nothing here repeats a rule tabs.css owns; the only addition is
  * this bar's own list items — flex rows, so tabs.css's `li > [data-md-tab]` share of the width
  * applies, and `min-inline-size: 0`, so a long title in a fixed row wraps to its second line and
  * truncates there (tabs.css, M3's "may wrap to a max second line if needed with truncation")