feat(ui): component redesign pass and fixes, release ui 0.8.87

Redesign
- Shared field foundation rules (duplicated across 15 form components and
  emitted globally) are now identical everywhere, so later copies no longer
  silently override earlier redesigns.
- Drawn checkbox and radio controls, white switch thumbs (the thumb was the
  text colour, a black blob in light mode), recessed field wells, keycap
  actions in Modal, Drawer, Popover, Toaster, Pagination, Stepper, DataTable.
- Menus (Dropdown, ContextMenu, Popover, Select dropdown, Navbar panels) share
  one flat raised panel with neutral hover rows and mono section labels.
- Alerts with an accent rail and icon chip; card headers without the grey
  band; accordion, collapse, list, list group, timeline, stats, metrics,
  chat, skeleton, avatar group, clipboard, splitter, section, sidebar,
  navbar and upload progress restyled.
- Chart rebuilt: nice y-axis ticks, gridlines, rounded bars, line and area
  modes, hover tooltips, hidden series leave the scale.

Fixes
- Checkbox and radio labels toggle their input again (empty for="" broke it).
- TimePicker kept every clicked time pressed; only the chosen hour and
  minute are pressed now, and nothing is pressed before a value exists.
- ColorPicker hex readout now follows the picked colour.
- Disabled FileInput no longer shows the native file-input text.
- Date and time panels float instead of pushing content.
- ContextMenu opened at the pointer closes on scroll.
- Drawer left/top/bottom placements slide from their own edge again.
- Image-only Card no longer renders an empty body strip.
- Timeline supports item.time, current/upcoming states, sizes and
  compact/alternate variants; showcase demos use distinct variants.
- ChatBubble: delivery receipts (sending/sent/delivered/read/failed/error)
  and meta aligned to its bubble.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

examples/component-showcase/app/pages/base.wrn

@@ -116,7 +116,7 @@ page BaseShowcase {
       <article class="catalog-card" data-interactive-preview="false">
         <div class="catalog-card-preview">
           <div class="catalog-card-glow" aria-hidden="true"></div>
-          <div class="catalog-card-stage"><ChatBubble size="default" color="primary" title="" description="" items='[{"text":"Hi Maya, is the new dashboard ready to review?","direction":"incoming","timestamp":"10:24"},{"text":"Yes! I have shared the latest version with you.","direction":"outgoing","timestamp":"10:25","status":"Delivered"},{"text":"Thanks, I will take a look this afternoon.","direction":"incoming","timestamp":"10:26"}]' oneSided="false" showAvatars="false" showMetadata="true" ariaLabel="Conversation" variant="default" class="" /></div>
+          <div class="catalog-card-stage"><ChatBubble size="default" color="primary" title="" description="" items='[{"text":"Hi Maya, is the new dashboard ready to review?","direction":"incoming","timestamp":"10:24"},{"text":"Yes! I have shared the latest version with you.","direction":"outgoing","timestamp":"10:25","receipt":"read"},{"text":"Thanks, I will take a look this afternoon.","direction":"incoming","timestamp":"10:26"},{"text":"Great. The release notes are attached too.","direction":"outgoing","timestamp":"10:27","receipt":"delivered"},{"text":"One more screenshot coming up.","direction":"outgoing","timestamp":"10:28","receipt":"sent"},{"text":"Uploading the final export now.","direction":"outgoing","timestamp":"10:29","receipt":"sending"},{"text":"Here is the invoice PDF.","direction":"outgoing","timestamp":"10:30","receipt":"failed","status":"Not delivered","actionLabel":"Retry"}]' oneSided="false" showAvatars="false" showMetadata="true" ariaLabel="Conversation" variant="default" class="" /></div>
         </div>
         <div class="catalog-card-body">
           <div><span class="catalog-card-category">Base</span><h2>Chat Bubble</h2><p>Theme-aware, responsive chat bubble component.</p></div>