fix(foundry,armada): sound audio streaming — HTTP/1.1, show duration, offer the original

PLN couldn't hear the Loituma stems and wanted the original too. The bytes/format
were fine (PCM_16/44.1k, audio/x-wav, 206 Range all verified) — the problems were
presentation + protocol:

- Both audio servers defaulted to HTTP/1.0, which closes the connection after each
  response. <audio> seeking fires many small Range requests, so HTTP/1.0 makes
  playback/seek flaky in real browsers. Set protocol_version="HTTP/1.1" on the
  Foundry Handler and armada RangeHandler (every response sets an exact
  Content-Length, so keep-alive is safe). Reliable streaming + seeking now.
- The stem players used preload="none", so they showed a misleading "0:00 / 0:00"
  until play — easy to read as "broken". Now preload="metadata": durations load and
  display (verified 164s on all five).
- The ORIGINAL is now offered on separated cards too (an "original" row), not just on
  raw catches — so PLN can A/B the source against each stem.

Verified end to end in Chromium: original + all 4 stems load 164s duration and
currentTime advances on play, no errors.

armada/serve.py

@@ -56,6 +56,9 @@ def _vibe_rank(qvec, n, drop=-1):
 
 
 class RangeHandler(SimpleHTTPRequestHandler):
+    # HTTP/1.1 keep-alive → reliable <audio> seeking (many small Range requests).
+    protocol_version = "HTTP/1.1"
+
     def do_GET(self):
         if self.path.split("?", 1)[0] in ("/vibe", "/similar"):
             return self._api()

tools/foundry/server.py

@@ -85,6 +85,10 @@ def _run_loops(job, workspace, slug, bars, top_n, mode):
 
 class Handler(SimpleHTTPRequestHandler):
     workspace: Path = Path()
+    # HTTP/1.1 keep-alive: <audio> seeking fires many small Range requests; reusing
+    # the connection makes streaming/seek reliable (HTTP/1.0 closes after each →
+    # stalls). Safe here because every response sets an exact Content-Length.
+    protocol_version = "HTTP/1.1"
 
     # ── routing ─────────────────────────────────────────────────────────
     def do_GET(self):

tools/foundry/ui/index.html

@@ -147,7 +147,7 @@ function fillModels(){
 function stemRow(slug, st){
   const div=document.createElement("div"); div.className="stem "+st.name;
   div.innerHTML=`<span class="tag">${st.name}</span>
-    <audio controls preload="none" src="/media/${slug}/${st.path}"></audio>
+    <audio controls preload="metadata" src="/media/${slug}/${st.path}"></audio>
     <a class="dl" href="/media/${slug}/${st.path}" download>⬇ wav</a>`;
   return div;
 }
@@ -161,11 +161,11 @@ function catchCard(c){
       <h2>${c.title}</h2>
       <div class="meta">${c.slug}${c.source_url?` · <a href="${c.source_url}" target="_blank">source</a>`:""}${c.duration?` · ${Math.round(c.duration)}s`:""}</div>
     </div><div class="row">${badge}${c.separated?"":`<button data-sep="${c.slug}">Separate</button>`}</div></div>`;
-  if(!c.separated){
-    el.insertAdjacentHTML("beforeend",
-      `<div class="stem"><span class="tag" style="color:var(--mute)">source</span>
-       <audio controls preload="none" src="/media/${c.slug}/${c.source_path}"></audio></div>`);
-  } else {
+  // the original is always offered — for raw catches AND alongside the stems
+  el.insertAdjacentHTML("beforeend",
+    `<div class="stem"><span class="tag" style="color:var(--mute)">original</span>
+     <audio controls preload="metadata" src="/media/${c.slug}/${c.source_path}"></audio></div>`);
+  if(c.separated){
     STEMS.forEach(name=>{ const s=c.stems.find(x=>x.name===name); if(s) el.appendChild(stemRow(c.slug,s)); });
     const lp=document.createElement("div"); lp.className="loops"; lp.id="lp-"+c.slug;
     lp.innerHTML=`<div class="loops-head"><span class="lbl">loops</span>