Extend mobile/tool/generate_sure_tokens.mjs to emit, from the canonical design/tokens/sure.tokens.json: a mode-aware box-shadow scale (shadowXs..shadowXl, parsed from shadow.xs..xl into List<BoxShadow>), plus the focus-ring (color.focus-ring) and bg-inverse (utility.bg-inverse) colors on SureTokenPalette. Regenerates mobile/lib/theme/sure_tokens.dart (import dart:ui -> package:flutter/painting.dart for BoxShadow/Offset); keeps the --check parity gate; adds token tests for the new values incl. the negative xl spread.
Radii are already complete (the source only defines md/lg); a type-scale is not in the token source, so both are intentionally untouched. The shadow-border composites are deferred (derivable in-widget as a shadow + a 1px border from existing border tokens). This unblocks SureCard/elevated surfaces.
Part of #2235.
* feat(mobile): align theme foundation with Sure tokens
Generate typed Flutter token constants from the canonical Sure token JSON and route the app through shared light/dark ThemeData construction. This keeps the first mobile design-system step scoped to foundation wiring and regression tests without restyling screens directly.
* fix(mobile): define Sure error container colors
Populate the manual Flutter ColorScheme error container pair from Sure tokens so validation and connection banners keep visible icon/text contrast. Add theme assertions for both light and dark modes.
* fix(mobile): preserve full-width action buttons
