fix(lotus): in-call mobile UI fixes (EC audit wave-2)

3-agent survey of the in-call UI at phone width + 2-agent review of the
staged diff. All changes are mobile-gated CSS (mobile-first @media on
Compound tokens), so desktop rendering is provably unchanged.

- CallFooter: wrap the control row and tighten gap/padding at <=500px so
  the buttons (incl. the destructive hangup) can never be clipped by the
  grid's overflow-x:hidden. A loudspeaker button was added to the bar
  without a shed rule, pushing 6-7 lg buttons past the viewport at
  320-500px.
- OneOnOnePortraitLayout: give the 1:1 self-view the same safe-area-aware
  inset as SpotlightExpandedLayout so it clears the home indicator /
  floating footer (was a bare 16px inset). Phone-only layout.
- GridTile: enlarge the always-visible camera-flip control to a 44px touch
  target on coarse pointers (was ~28px).
- ReactionToggleButton: enlarge reaction-picker emoji buttons to 44px at
  <=420px (were ~32px); five still fit a 360px drawer row.
- Tabs: scroll the horizontal tab row on the inline axis (overflow-x) so
  the Settings tabs don't clip in a phone drawer.
- SpotlightLandscapeLayout: shrink the 180px filmstrip rail to 132px on
  short landscape phones (max-height:400px) so the spotlight isn't a sliver.

Gates: tsc 0, prettier clean, affected vitest pass. No TS changed.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/tabs/Tabs.module.css

@@ -12,7 +12,12 @@ Please see LICENSE in the repository root for full details.
 }
 
 .tabList {
-  overflow-y: auto;
+  /* The tab row is horizontal, so scroll along the inline axis when the tabs
+     exceed the width (e.g. the Settings modal as a phone drawer). The prior
+     overflow-y:auto expressed the wrong axis; make the horizontal intent
+     explicit and hide the scrollbar. */
+  overflow-x: auto;
+  overflow-y: hidden;
   max-width: 100%;
 
   /*no scrollbars*/
@@ -24,4 +29,5 @@ Please see LICENSE in the repository root for full details.
   /*no scrollbars*/
   background: transparent; /* Chrome/Safari/Webkit */
   width: 0px;
+  height: 0px;
 }