feat: M1 admin console — all 10 remaining pages + signal/quality/ops infrastructure

Admin console (issues #63–72):
- Event stream viewer: live-tail ring buffer (500 events) with subject/user filters
- Feature store browser: per-user feature vector history from ml/serving
- Model registry panel: MLflow embed at /admin/models
- Experiment dashboard: LinUCB per-user stats (pulls, reward, θ) + bandit reset
- Recommendation log: per-tip explainability (policy, score, features, latency)
- Reward analytics: daily reaction breakdown + per-policy compare
- Data quality widget: missing-feature rate, stale-token rate, daily completeness
- Ops actions: replay-signal, policy enable/disable; user actions link to Users page
- SQL runner: read-only SELECT runner with saved queries
- Health rollup: fan-out to api/ml/sqlite/event-bus with auto-refresh

Backend:
- tip_scores table: logs features+policy+score+latency at every scoring call (#67)
- saved_queries table: per-admin saved SQL (#71)
- Event bus: 500-event ring buffer + tail() API (#63)
- Admin routes: /events, /tips, /reward-analytics, /data-quality, /health,
  /policies, /replay-signal, /sql, /saved-queries endpoints
- /api/ml/* admin-gated proxy to ml/serving (#64, #66)
- Shadow-policy registry in recommender (#56)

ML serving:
- /reset/{user_id}: clear bandit state + feature history (#66)
- /stats/{user_id}: pulls, cumulative reward, estimated mean, θ (#66)
- /features/{user_id}: last 100 feature vectors logged at scoring time (#64)
- Meta (pulls, rewards) persisted alongside A/b matrices

Web:
- Tip action sheet adds Helpful / Not helpful buttons (#62)
- TipFeedback type extended with helpful/not_helpful actions
- Rewards mapped: helpful=+0.5, not_helpful=−0.5

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/admin/src/app/data-quality/page.tsx

@@ -0,0 +1,89 @@
+'use client';
+
+import { useEffect, useState } from 'react';
+import { AdminShell } from '@/components/AdminShell';
+import { getDataQuality } from '@/lib/api';
+
+function Pct({ value }: { value: number }) {
+  const pct = (value * 100).toFixed(1);
+  const color = value < 0.05 ? 'text-green-400' : value < 0.2 ? 'text-yellow-400' : 'text-red-400';
+  return <span className={color}>{pct}%</span>;
+}
+
+export default function DataQualityPage() {
+  const [data, setData] = useState<Awaited<ReturnType<typeof getDataQuality>> | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState('');
+
+  useEffect(() => {
+    getDataQuality()
+      .then(setData)
+      .catch((e) => setError(e.message))
+      .finally(() => setLoading(false));
+  }, []);
+
+  return (
+    <AdminShell>
+      <div className="space-y-6">
+        <h1 className="text-xl font-semibold">Data quality</h1>
+        {error && <p className="text-red-400 text-sm">{error}</p>}
+        {loading && <p className="text-gray-500 text-sm">Loading…</p>}
+
+        {data && (
+          <>
+            <div className="grid grid-cols-2 gap-4 md:grid-cols-4">
+              <div className="bg-gray-900 border border-gray-800 rounded p-4">
+                <div className="text-xs text-gray-500 mb-1">Scoring calls (30d)</div>
+                <div className="text-2xl font-semibold">{data.scoringCallsLast30d}</div>
+              </div>
+              <div className="bg-gray-900 border border-gray-800 rounded p-4">
+                <div className="text-xs text-gray-500 mb-1">Missing feature rate</div>
+                <div className="text-2xl font-semibold"><Pct value={data.missingFeatureRate} /></div>
+              </div>
+              <div className="bg-gray-900 border border-gray-800 rounded p-4">
+                <div className="text-xs text-gray-500 mb-1">Integration tokens</div>
+                <div className="text-2xl font-semibold">{data.totalTokens}</div>
+              </div>
+              <div className="bg-gray-900 border border-gray-800 rounded p-4">
+                <div className="text-xs text-gray-500 mb-1">Stale token rate (&gt;7d)</div>
+                <div className="text-2xl font-semibold"><Pct value={data.staleTokenRate} /></div>
+              </div>
+            </div>
+
+            <div className="space-y-2">
+              <h2 className="text-sm font-medium text-gray-400">Daily feature completeness (14d)</h2>
+              <table className="w-full text-xs">
+                <thead>
+                  <tr className="border-b border-gray-800 text-gray-500 text-left">
+                    <th className="py-2 pr-4">Date</th>
+                    <th className="py-2 pr-4">Scoring calls</th>
+                    <th className="py-2 pr-4">With features</th>
+                    <th className="py-2 pr-4">Coverage</th>
+                    <th className="py-2">Avg candidates</th>
+                  </tr>
+                </thead>
+                <tbody>
+                  {data.dailyQuality.map((row) => {
+                    const coverage = row.total > 0 ? row.withFeatures / row.total : 0;
+                    return (
+                      <tr key={row.date} className="border-b border-gray-800/50">
+                        <td className="py-1.5 pr-4 font-mono text-gray-500">{row.date}</td>
+                        <td className="py-1.5 pr-4 text-gray-300">{row.total}</td>
+                        <td className="py-1.5 pr-4 text-gray-300">{row.withFeatures}</td>
+                        <td className="py-1.5 pr-4"><Pct value={coverage} /></td>
+                        <td className="py-1.5 text-gray-300">{row.avgCandidates?.toFixed(1) ?? '—'}</td>
+                      </tr>
+                    );
+                  })}
+                  {data.dailyQuality.length === 0 && (
+                    <tr><td colSpan={5} className="py-4 text-center text-gray-600">No data yet</td></tr>
+                  )}
+                </tbody>
+              </table>
+            </div>
+          </>
+        )}
+      </div>
+    </AdminShell>
+  );
+}