fix(headers): keep list-page header actions on one row on mobile

The medications header used flex-wrap, so its action group (take-all
+ customize wrench + Add) dropped to a second row below the title on
narrow viewports. Drop the wrap and let the title block shrink: title
div gets min-w-0, subtitle truncates, action group keeps shrink-0 —
the wrench and Add stay top-right inline with the heading.

The mood, measurements and dashboard headers shared the same latent
root cause (title div missing min-w-0, subtitle/greeting not
truncating, action group not shrink-0). Apply the same minimal guard
so none of them can wrap or compress the actions either.

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

src/components/dashboard/dashboard-header.tsx

@@ -78,7 +78,7 @@ export function DashboardHeader({
         showGreeting && "sm:items-start",
       )}
     >
-      <div>
+      <div className="min-w-0">
         <h1 className="text-2xl font-bold tracking-tight">
           {t("dashboard.title")}
         </h1>
@@ -89,13 +89,13 @@ export function DashboardHeader({
              keeps the header from collapsing/growing around that swap. */
           <p
             data-slot="dashboard-header-greeting"
-            className="text-muted-foreground mt-1 min-h-5 text-sm"
+            className="text-muted-foreground mt-1 min-h-5 truncate text-sm"
           >
             {welcomeText}
           </p>
         ) : null}
       </div>
-      <div className="flex items-center gap-2">
+      <div className="flex shrink-0 items-center gap-2">
         {/* Customize shortcut to the dashboard-customization settings
             (the tile/layout editor at /settings/dashboard). Sits to
             the left of the add button as a monochrome ghost icon, with