feat: Apple-grade pass — scale, type, photographic hero, de-noise, single-signal chrome, lighter header

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012jWfn3RwPfFGTtBddm36Uy

src/pages/proposals.astro

@@ -2,16 +2,11 @@
 import Base from '../layouts/Base.astro';
 ---
 <Base title="CTAO Science Portal — Proposals" description="Observation proposal submission (mock)">
-  <section class="hero-band">
-    <div class="band-bg" aria-hidden="true"></div>
-    <div class="container hero">
-      <div class="eyebrow">Proposal Submission</div>
-      <h1>Observation proposals</h1>
-      <p>Submit observation proposals, including ToO and MWL requests</p>
-    </div>
-  </section>
-
   <section class="band--moon">
+    <header class="container page-head">
+      <h1>Observation proposals</h1>
+      <p class="standfirst">Submit observation proposals, including ToO and MWL requests.</p>
+    </header>
     <div class="container page">
     <span class="badge-mock">Mock — no submission logic</span>
     <span class="badge-ext">Planned integration: Proposal Handling System (APC team)</span>