feat(ui): share view on steward.css; breadcrumbs everywhere they belong; focus ring; tables scroll in their card (#5095)

#5095 "Share view on the shared stylesheet; breadcrumbs, focus-visible and
wide tables".

- dashboard/share_view.html loads theme.css and steward.css; its own copy of
  the old purple palette is gone. Only the read-only frame and the x/y/w/h
  grid stay inline, written in tokens. HEX_CEILING 75 -> 58.
- Breadcrumbs on settings/general, settings/thresholds, the dashboard share
  page and share-link-created. tests/test_breadcrumbs.py fails on any page
  extending base.html without a crumbs() trail, unless it is on the named
  list of section top pages, logged-out and error pages (rule 134).
- :focus-visible draws --fs-focus-ring on links, buttons, summaries, inputs
  and anything with tabindex.
- Any card holding a .table scrolls sideways (card:has(table.table)), so a
  wide table no longer widens the page at phone width; .card-flush scrolls
  too, main gets min-width:0, and .table-wrap covers a table outside a card.
- tests/test_share_view.py renders the share view: shared sheets, no hex
  colour, escaped name, widgets loading through the share token.

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

tests/test_style_tokens.py

@@ -22,7 +22,7 @@ _USED = re.compile(r"var\(\s*(--[\w-]+)")
 # string -- but not an HTML attribute's value (href="#abc" is a link to an id).
 _HEX = re.compile(r"""(?:[:(,]\s*|(?<![\w-]=)['"])#(?:[0-9a-fA-F]{8}|[0-9a-fA-F]{6}|[0-9a-fA-F]{3})(?![0-9a-zA-Z_-])""")
 
-HEX_CEILING = 75  # measured 2026-10-06 (#5092); lower it as pages move onto tokens, never raise it
+HEX_CEILING = 58  # 75 at #5092, 58 once the share view used steward.css (#5095); only lower it
 
 
 def _sheets():