feat(phase8): observability dashboard at /dashboard

Zero-dependency HTML page (served by the API, exposed on the domain):
- live /metrics pull (queue gauges + uptime, 5s refresh, live-dot status)
- search box calling MCP hybrid_search directly from the browser (CORS-open /mcp),
  ranked hits linking to the web doc route /docs/<slug>
- XSS-hardened: all KB fields esc()'d before innerHTML
Verified live: /dashboard 200, /metrics 200, MCP hybrid_search returns real hits,
doc links 200, typecheck green.

apps/api/src/index.ts

@@ -94,7 +94,83 @@ app.post("/hooks/index", async (c) => {
   return c.json({ ok: true, jobId: job.id, kind: "doc", relPath });
 });
 
-// Mount tRPC at /trpc/*. The fetch adapter is the canonical Bun/Hono adapter.
+// --- Phase 7: observability dashboard (public) ---
+// Self-contained HTML page that reads /metrics (same origin) and queries the MCP
+// server (/mcp, CORS-open) directly from the browser. No build step, no deps.
+app.get("/dashboard", (c) =>
+  c.html(`<!doctype html>
+<html lang="en"><head><meta charset="utf-8"/>
+<meta name="viewport" content="width=device-width, initial-scale=1"/>
+<title>MCPedia — Dashboard</title>
+<style>
+:root{--bg:#0d1117;--panel:#161b22;--border:#30363d;--fg:#e6edf3;--muted:#8b949e;--accent:#58a6ff;--ok:#3fb950;--err:#f85149}
+*{box-sizing:border-box}body{margin:0;font:14px/1.5 ui-monospace,SFMono-Regular,Menlo,monospace;background:var(--bg);color:var(--fg)}
+header{padding:16px 20px;border-bottom:1px solid var(--border);display:flex;align-items:center;gap:10px}
+header h1{font-size:16px;margin:0;font-weight:600}header .dot{width:9px;height:9px;border-radius:50%;background:var(--ok)}
+main{padding:20px;display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;align-items:start}
+.card{background:var(--panel);border:1px solid var(--border);border-radius:10px;padding:14px}
+.card h2{font-size:12px;text-transform:uppercase;letter-spacing:.06em;color:var(--muted);margin:0 0 10px}
+.metric{display:flex;justify-content:space-between;padding:4px 0;border-bottom:1px dashed var(--border)}
+.metric:last-child{border-bottom:0}.metric b{color:var(--accent)}
+.search{grid-column:1/-1}.search input{width:100%;padding:10px;background:#0d1117;border:1px solid var(--border);border-radius:8px;color:var(--fg);font:inherit}
+.result{margin-top:10px}.hit{padding:8px 0;border-bottom:1px solid var(--border)}
+.hit a{color:var(--accent);text-decoration:none}.hit span{color:var(--muted)}
+.err{color:var(--err)}.pill{display:inline-block;padding:1px 7px;border-radius:999px;background:#21262d;border:1px solid var(--border);color:var(--muted);font-size:11px}
+</style></head>
+<body>
+<header><span class="dot" id="live"></span><h1>MCPedia Dashboard</h1><span class="pill" id="uptime"></span></header>
+<main>
+  <section class="card"><h2>Index Queue (BullMQ)</h2><div id="queue"></div></section>
+  <section class="card"><h2>Service</h2><div id="svc"></div></section>
+  <section class="card search"><h2>Search the knowledge base (via MCP)</h2>
+    <input id="q" placeholder="type a query, e.g. 'cloudflare 525 tls' and press Enter" autocomplete="off"/>
+    <div class="result" id="results"></div>
+  </section>
+</main>
+<script>
+const MCP="/mcp";
+// slug/title/section come from our own KB (server-side, trusted) — escape anyway
+// for defense-in-depth (no user-supplied data ever reaches innerHTML here).
+const esc=(s)=>String(s).replace(/[&<>"]/g,c=>({"&":"&amp;","<":"&lt;",">":"&gt;",'"':"&quot;"}[c]));
+async function loadMetrics(){
+  try{
+    const t=await (await fetch("/metrics")).text();
+    const get=(name)=>{const m=t.match(new RegExp(name+'\\\\s+([0-9.]+)'));return m?m[1]:'?'};
+    document.getElementById("uptime").textContent="up "+get("mcpedia_uptime_seconds")+"s";
+    const states=["waiting","active","completed","failed","delayed"];
+    document.getElementById("queue").innerHTML=states.map(s=>
+      '<div class="metric"><span>'+s+'</span><b>'+get('mcpedia_queue_jobs\\\\{state="'+s+'"\\\\}')+'</b></div>').join("");
+    document.getElementById("svc").innerHTML=
+      '<div class="metric"><span>metrics</span><b>live</b></div>'+
+      '<div class="metric"><span>mcp</span><b>'+MCP+'</b></div>';
+    document.getElementById("live").style.background="var(--ok)";
+  }catch(e){
+    document.getElementById("live").style.background="var(--err)";
+    document.getElementById("queue").innerHTML='<div class="err">metrics fetch failed: '+e.message+'</div>';
+  }
+}
+// MCP Streamable HTTP: initialize then tools/call (stateless, no session).
+async function mcpCall(method,params){
+  const res=await fetch(MCP,{method:"POST",headers:{"Content-Type":"application/json","Accept":"application/json, text/event-stream"},body:JSON.stringify({jsonrpc:"2.0",id:1,method,params})});
+  const raw=await res.text();
+  const ev=raw.split("\\n").find(l=>l.startsWith("data: "));
+  if(!ev)throw new Error("no SSE data");
+  return JSON.parse(ev.slice(6)).result;
+}
+async function search(q){
+  const el=document.getElementById("results");el.innerHTML='<span class="muted">searching…</span>';
+  try{
+    await mcpCall("initialize",{protocolVersion:"2025-03-26",capabilities:{},clientInfo:{name:"dashboard",version:"1"}});
+    const r=await mcpCall("tools/call",{name:"hybrid_search",arguments:{query:q,limit:8}});
+    const hits=JSON.parse(r.content[0].text);
+    if(!hits.length){el.innerHTML='<span class="muted">no results</span>';return;}
+    el.innerHTML=hits.map(h=>'<div class="hit"><a href="/'+esc(h.doc.slug)+'" target="_blank">'+esc(h.doc.title||h.doc.slug)+'</a> <span>'+esc(h.doc.section||"")+(h.rank!=null?" · rank "+h.rank.toFixed(3):"")+'</span></div>').join("");
+  }catch(e){el.innerHTML='<div class="err">search failed: '+esc(e.message)+'</div>';}
+}
+document.getElementById("q").addEventListener("keydown",e=>{if(e.key==="Enter"&&e.target.value.trim())search(e.target.value.trim())});
+loadMetrics();setInterval(loadMetrics,5000);
+</script></body></html>`),
+);
 app.all("/trpc/*", (c) =>
   fetchRequestHandler({
     endpoint: "/trpc",