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>

packages/ui/components/Nav.wrn

@@ -223,16 +223,17 @@ component Nav {
       display: flex;
       align-items: center;
       gap: 0.45rem;
-      padding: 0.45rem 0.7rem;
+      padding: 0.4rem 0.7rem;
       border-radius: var(--wrn-radius-sm);
       color: var(--wrn-color-text-muted);
-      font-size: 0.9rem;
-      font-weight: 600;
+      font-size: 0.875rem;
+      font-weight: 550;
       text-decoration: none;
+      transition: background-color 120ms ease, color 120ms ease;
     }
 
     .wrn-nav__link:hover {
-      background: var(--wrn-color-surface-soft);
+      background: var(--wrn-color-surface-muted, var(--wrn-color-surface-soft));
       color: var(--wrn-color-text);
     }
 
@@ -242,8 +243,9 @@ component Nav {
     }
 
     .wrn-nav__link[data-active="true"] {
-      background: color-mix(in srgb, var(--nav-accent) 16%, transparent);
-      color: var(--nav-accent);
+      background: var(--wrn-color-surface-raised, var(--wrn-color-surface));
+      color: var(--wrn-color-text);
+      box-shadow: 0 0 0 1px var(--wrn-color-border), var(--wrn-shadow-1);
     }
 
     .wrn-nav__link[aria-disabled="true"] {
@@ -252,11 +254,13 @@ component Nav {
     }
 
     .wrn-nav__badge {
-      padding: 0.05rem 0.4rem;
+      padding: 0.0625rem 0.4rem;
       border-radius: 999px;
-      background: color-mix(in srgb, var(--nav-accent) 16%, transparent);
-      color: var(--nav-accent);
-      font-size: 0.72rem;
+      background: var(--wrn-color-surface-muted, var(--wrn-color-surface-2));
+      color: var(--wrn-color-text-muted);
+      font-size: 0.68rem;
+      font-weight: 650;
+      font-variant-numeric: tabular-nums;
     }
 
     .wrn-nav__arrow {
@@ -272,15 +276,15 @@ component Nav {
     .wrn-nav__submenu {
       position: absolute;
       z-index: 30;
-      top: 100%;
+      top: calc(100% + 0.25rem);
       left: 0;
       min-width: 12rem;
       margin: 0;
-      padding: 0.35rem;
+      padding: 0.3rem;
       border: 1px solid var(--wrn-color-border);
-      border-radius: var(--wrn-radius-md);
-      background: var(--wrn-color-surface);
-      box-shadow: var(--wrn-shadow-1);
+      border-radius: var(--wrn-radius);
+      background: var(--wrn-color-surface-raised, var(--wrn-color-surface));
+      box-shadow: var(--wrn-highlight-edge, none), var(--wrn-shadow-3);
       list-style: none;
       opacity: 0;
       visibility: hidden;