fix(chrome): reserve the smart-search hint in the phone mode-home composer slot

src/app/globals.css

@@ -120,11 +120,27 @@
      client host adopts them. Without this structural reserve, Therapy moved the
      entire action stack when hydration relocated the composer (CLS 0.248).
      These are layout tokens, not a second v2 colour/theme source. */
-  /* Re-measured after the privacy notice stopped spending a full 48px tap box
-     on its own wrapped line: the settled phone composer block is 106px, so the
-     old 7.625rem (122px) left a 16px empty band under it. The wide value was
-     already exact (88px) and the notice is a single 16px line from sm up. */
-  --spacing-mode-home-composer-phone: 6.625rem;
+  /* Re-measured 2026-08-19 at 390px across six mode homes (therapy-compass,
+     dsm, forms, factsheets, specifiers, and the shared `/` home): every one
+     settles at 162px, not the 106px this reserved. The 56px difference is the
+     smart-search hint, which `UniversalSearchCommandSurface` renders INSIDE
+     this slot above the composer: a 48px hint row plus the 8px flex gap that
+     separates it from the composer (`gap-2` on `.universal-command-surface` —
+     the `gap-1` in that same expression is the bottom-dock placement, not this
+     slot). The earlier measurement counted only the composer pill plus the
+     privacy notice, before that hint existed. Under-reserving it meant the slot
+     grew on portal adoption and pushed the action and pill stacks down on every
+     ticket-bearing mode home (measured CLS: specifiers 0.055, dsm 0.047,
+     therapy 0.042, `/` 0.020, forms 0.019, factsheets 0.017). Both the hint row
+     and its gap are fixed-height on phone, so 162px is exact: the settled
+     layout is unchanged and only the pre-adoption reserve grows.
+
+     The wide value is knowingly still short (88px against a settled 160px at
+     1280 and 199px at 800). It is NOT simply raised to match: the sm+ surface
+     swaps the phone ticket for a prompt-chip row that rewraps with viewport
+     width, so no single static value is correct at every width. That needs a
+     different mechanism and is tracked separately. */
+  --spacing-mode-home-composer-phone: 10.125rem;
   --spacing-mode-home-composer-wide: 5.5rem;
 
   /* Hero medallion. Scales continuously with the viewport the way --text-hero

tests/search-route-ownership.test.ts

@@ -214,7 +214,11 @@ describe("shared-search route ownership", () => {
     expect(homeTemplateSource).not.toMatch(
       /mode-home-composer-slot block min-h-\[var\(--spacing-mode-home-composer-phone\)\]/,
     );
-    expect(globalsSource).toContain("--spacing-mode-home-composer-phone: 6.625rem");
+    // 162px: the settled phone composer block, measured across six mode homes.
+    // It must equal that height, not merely be non-zero — a reserve short of the
+    // settled height is what shifted the action/pill stacks on adoption, and a
+    // reserve above it would leave a permanent empty band.
+    expect(globalsSource).toContain("--spacing-mode-home-composer-phone: 10.125rem");
     expect(globalsSource).toContain("--spacing-mode-home-composer-wide: 5.5rem");
   });