feat: behind-the-scenes 👍/👎 rating system (fine-tune data collection)

Brian can rate Lyra's outputs as he uses her; each rating is stored as a
(context, content, rating) triple — the shape a future fine-tune / preference
dataset wants, collected passively during real use.

- memory: ratings table + add_rating (upsert: one row per item, re-rating
  replaces), list_ratings, rating_counts
- server: POST /rate, GET /ratings/counts, GET /ratings/export (JSONL download)
- chat UI: subtle 👍/👎 on each assistant reply, captures the prompting message
  as context
- journal/reflection UI: 👍/👎 on each thought
- tests: counts + upsert-replace behavior

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lyra/web/static/index.html

@@ -354,12 +354,46 @@
     return out.join("\n");
   }
 
+	function addRateBar(div) {
+	  const bar = document.createElement("div");
+	  bar.className = "rate-bar";
+	  const up = document.createElement("button");
+	  up.className = "rate-btn"; up.textContent = "👍"; up.title = "Good — more like this";
+	  const down = document.createElement("button");
+	  down.className = "rate-btn"; down.textContent = "👎"; down.title = "Off — less like this";
+	  up.addEventListener("click", () => rateMessage(div, 1, up, down));
+	  down.addEventListener("click", () => rateMessage(div, -1, up, down));
+	  bar.appendChild(up); bar.appendChild(down);
+	  div.appendChild(bar);
+	}
+
+	function rateMessage(div, value, up, down) {
+	  // context = the nearest preceding user message
+	  let ctx = "", p = div.previousElementSibling;
+	  while (p) {
+	    if (p.classList && p.classList.contains("user")) { ctx = p.textContent; break; }
+	    p = p.previousElementSibling;
+	  }
+	  fetch(`${RELAY_BASE}/rate`, {
+	    method: "POST", headers: { "Content-Type": "application/json" },
+	    body: JSON.stringify({ kind: "chat", rating: value, content: div.dataset.raw || "", context: ctx, session_id: currentSession })
+	  }).catch(() => {});
+	  up.classList.toggle("rated", value === 1);
+	  down.classList.toggle("rated", value === -1);
+	}
+
 	function addMessage(role, text, autoScroll = true) {
 	  const messagesEl = document.getElementById("messages");
 
 	  const msgDiv = document.createElement("div");
 	  msgDiv.className = `msg ${role}`;
-	  if (role === "assistant") { msgDiv.innerHTML = renderMarkdown(text); } else { msgDiv.textContent = text; }
+	  if (role === "assistant") {
+	    msgDiv.innerHTML = renderMarkdown(text);
+	    msgDiv.dataset.raw = text;
+	    addRateBar(msgDiv);
+	  } else {
+	    msgDiv.textContent = text;
+	  }
 	  messagesEl.appendChild(msgDiv);
 
 	  // Auto-scroll to bottom if enabled

lyra/web/static/journal.html

@@ -52,6 +52,12 @@
     .time { color: var(--fade); font-size: .72rem; }
     .src  { color: var(--fade); font-size: .68rem; opacity: .7; }
     .text { font-size: .98rem; line-height: 1.55; }
+    .jrate { display: flex; gap: 8px; margin-top: 6px; opacity: .35; }
+    .entry:hover .jrate { opacity: .85; }
+    .jr { background: none; border: none; cursor: pointer; font-size: .85rem; padding: 2px 5px;
+          border-radius: 5px; filter: grayscale(.6); -webkit-tap-highlight-color: transparent; }
+    .jr:hover { filter: none; background: rgba(255,122,0,.12); }
+    .jr.rated { filter: none; background: rgba(255,122,0,.25); opacity: 1; }
     .empty { color: var(--fade); text-align: center; padding: 44px 16px; }
     .hidden { display: none !important; }
   </style>
@@ -115,12 +121,29 @@
               ${e.source ? `<span class="src">via ${esc(e.source)}</span>` : ''}
             </div>
             <div class="text">${esc(e.content)}</div>
+            <div class="jrate">
+              <button class="jr" data-id="${e.id}" data-val="1">👍</button>
+              <button class="jr" data-id="${e.id}" data-val="-1">👎</button>
+            </div>
           </div>
         </div>`;
       }
       root.innerHTML = html;
     }
 
+    // 👍/👎 on a thought -> /rate (fine-tune signal)
+    root.addEventListener('click', (ev) => {
+      const b = ev.target.closest('.jr'); if (!b) return;
+      const e = entries.find(x => String(x.id) === b.dataset.id); if (!e) return;
+      fetch('/rate', {
+        method: 'POST', headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ kind: e.kind, rating: Number(b.dataset.val), content: e.content, ref: e.id })
+      }).catch(() => {});
+      const bar = b.parentElement;
+      bar.querySelectorAll('.jr').forEach(x => x.classList.remove('rated'));
+      b.classList.add('rated');
+    });
+
     async function load(){
       try {
         const r = await fetch('/journal/data', { cache: 'no-store' });

lyra/web/static/style.css

@@ -994,3 +994,14 @@ select:hover {
   border-radius: 6px; padding: 10px 12px; margin: 8px 0; overflow-x: auto;
 }
 .msg.assistant pre code { background: none; padding: 0; font-size: 0.85em; }
+
+/* Behind-the-scenes 👍/👎 feedback (fine-tune signal) — subtle until hovered. */
+.rate-bar { display: flex; gap: 6px; margin-top: 7px; opacity: 0.3; transition: opacity .15s; }
+.msg.assistant:hover .rate-bar { opacity: 0.85; }
+.rate-btn {
+  background: none; border: none; cursor: pointer; font-size: 0.85rem;
+  padding: 2px 5px; border-radius: 5px; line-height: 1; filter: grayscale(0.6);
+  -webkit-tap-highlight-color: transparent;
+}
+.rate-btn:hover { filter: none; background: rgba(255,122,0,0.12); }
+.rate-btn.rated { filter: none; background: rgba(255,122,0,0.25); opacity: 1; }