Academy v4: 3 research-backed lessons (30 slides + audio); new bean logo; custom plan/lot names

Co-Authored-By: Claude Fable 5 <[email protected]>

public/index.html

@@ -17,7 +17,7 @@
     <div class="app-shell">
       <nav class="side-nav" id="side-nav" aria-label="Main navigation">
         <div class="side-nav-brand">
-          <span class="brand-mark" aria-hidden="true">◐</span>
+          <img class="brand-mark" src="/brand-mark.svg?v=__ASSET_VERSION__" alt="" aria-hidden="true" />
           <span class="brand-name">Roast Planner</span>
         </div>
         <div id="nav-links"></div>