sync: bug fixes + eval system from private repo

- Fix chunk_status: pass chunk_status/chunk/metadata to context builder
- Fix vector search: scope by node_id BEFORE similarity search
- Add eval logging system (RAH_EVALS_LOG=1)
- Add eval dashboard at /evals
- Add vitest for testing

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/evals/page.tsx

@@ -0,0 +1,39 @@
+import { notFound } from 'next/navigation';
+import { loadEvalTraces } from '@/services/evals/evalsStore';
+import EvalsClient from './EvalsClient';
+import { scenarios } from '../../tests/evals/scenarios';
+
+export const dynamic = 'force-dynamic';
+
+export default function EvalsPage() {
+  const evalsEnabled = process.env.RAH_EVALS_LOG === '1' || process.env.RAH_EVALS_LOG === 'true';
+  if (process.env.NODE_ENV === 'production' || !evalsEnabled) {
+    notFound();
+  }
+
+  const traces = loadEvalTraces(25);
+  const scenarioList = scenarios.map((scenario) => ({
+    id: scenario.id,
+    name: scenario.name,
+    description: scenario.description,
+    tools: scenario.tools,
+    enabled: scenario.enabled,
+    notes: scenario.notes,
+  }));
+
+  return (
+    <div style={{ height: '100vh', overflowY: 'auto', background: '#f5f5f5', color: '#111' }}>
+      <div style={{ padding: 24, maxWidth: 1200, margin: '0 auto', fontFamily: 'ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, \"Liberation Mono\", \"Courier New\", monospace' }}>
+        <div style={{ position: 'sticky', top: 0, background: '#f5f5f5', paddingBottom: 12, marginBottom: 12, zIndex: 1 }}>
+          <h1 style={{ fontSize: 24, marginBottom: 6 }}>Eval Traces</h1>
+          <div style={{ color: '#444' }}>Trace table on top, full span detail below.</div>
+        </div>
+        {traces.length === 0 ? (
+          <p>No eval traces found. Run evals with RAH_EVALS_LOG=1.</p>
+        ) : (
+          <EvalsClient traces={traces} scenarioList={scenarioList} />
+        )}
+      </div>
+    </div>
+  );
+}