feat(rag): steering notes — tune how Brain answers, stored in Postgres and injected into every system prompt

frontend/index.html

@@ -21,6 +21,14 @@
         <a href="/" class="nav-link is-active" aria-current="page">Chat</a>
         <a href="/sources.html" class="nav-link">Sources</a>
       </nav>
+      <!-- Phase 15: open the tuning-notes panel (stored in Postgres, read
+           into every system prompt) — chat page only. -->
+      <button type="button" class="steering-toggle" id="steering-toggle"
+              aria-expanded="false" aria-controls="steering-panel">
+        <svg aria-hidden="true" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.7" stroke-linecap="round"><path d="M4 7h10M18 7h2M4 17h4M12 17h8"/><circle cx="15.5" cy="7" r="2.2"/><circle cx="9.5" cy="17" r="2.2"/></svg>
+        <span class="steering-label">Tuning</span>
+        <span class="steering-count" id="steering-count">0</span>
+      </button>
       <!-- Phase 14: reset the local (localStorage) conversation — chat page only. -->
       <button type="button" class="new-chat-btn" id="new-chat-btn" aria-label="New chat">
         <svg aria-hidden="true" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.7" stroke-linecap="round"><path d="M12 5v14M5 12h14"/></svg>
@@ -36,6 +44,18 @@
         <span id="kb-banner-text"></span>
       </div>
 
+      <!-- Phase 15: tuning-notes panel (stored notes, newest first). -->
+      <section class="steering-panel" id="steering-panel" role="region"
+               aria-label="Tuning notes" hidden>
+        <div class="steering-panel-head">
+          <h2 class="steering-panel-title">Tuning notes</h2>
+          <p class="steering-panel-sub">Every note below steers all future answers.</p>
+        </div>
+        <ul class="steering-list" id="steering-list"></ul>
+        <p class="steering-empty" id="steering-empty">No tuning notes yet — press “Tune” under any answer to add one.</p>
+      </section>
+      <p class="visually-hidden" id="steering-announcer" role="status" aria-live="polite" aria-atomic="true"></p>
+
       <section class="messages" id="messages" aria-live="polite" aria-label="Conversation with Brain of Reese">
         <div class="empty-state" id="empty-state">
           <div class="empty-state-glyph" aria-hidden="true">