Fix Playwright tests: add h1 heading role to app header, remove duplicate Plans h2

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/src/App.svelte

@@ -920,7 +920,7 @@ Image estimate: ${imageEstimate}` },
             <button class="grid h-9 w-9 place-items-center rounded-xl bg-blue-600 text-white hover:bg-blue-700 lg:hidden" type="button" on:click={() => menuOpen = true} aria-label="Open menu">
               <svg viewBox="0 0 20 20" fill="currentColor" width="18" height="18"><path fill-rule="evenodd" d="M3 5a1 1 0 011-1h12a1 1 0 110 2H4a1 1 0 01-1-1zm0 5a1 1 0 011-1h12a1 1 0 110 2H4a1 1 0 01-1-1zm0 5a1 1 0 011-1h12a1 1 0 110 2H4a1 1 0 01-1-1z" clip-rule="evenodd"/></svg>
             </button>
-            <div class="truncate text-base font-bold text-slate-900">{pages.find(item => item.id === page)?.label || 'Dashboard'}</div>
+            <h1 class="truncate text-base font-bold text-slate-900">{pages.find(item => item.id === page)?.label || 'Dashboard'}</h1>
           </div>
           <button class="rounded-lg border border-slate-200 px-3 py-1.5 text-sm font-semibold text-slate-600 hover:border-slate-300 hover:text-slate-900" type="button" on:click={logout}>Sign out</button>
         </div>

web/src/PlansPage.svelte

@@ -75,10 +75,7 @@
 </script>
 
 <section class="space-y-4">
-  <div>
-    <h2 class="text-xl font-bold">Plans</h2>
-    <p class="text-sm text-slate-500">Your personal weight-loss plan, updated as you log meals and progress. Powered by AI, built from your profile.</p>
-  </div>
+  <p class="text-sm text-slate-500">Your personal weight-loss plan, updated as you log meals and progress. Powered by AI, built from your profile.</p>
 
   <div class="grid gap-4 xl:grid-cols-[0.8fr_1.2fr]">
     <section class="card">