feat(T5/dashboard): import DBF idempotent + nomenclator browser + audit CSV + stare RAR

T5 (tools/import_dbf.py): citire prestatii_rar.DBF / mapare_prestatii.DBF cu
dbfread, raport dry-run (randuri valide/duplicate/goale, mapari orfane = cod
necunoscut in nomenclator), --commit cu upsert idempotent in tranzactie.

Dashboard: browser nomenclator, indicator stare RAR (indisponibil? derivat din
ultimul login < 30h, coada arata ultima stare locala), export audit CSV
(/v1/audit/export?status=sent|all&date_from&date_to, b64Image exclus,
coloana purge_after pentru retentia 90z).

Verify: 11 teste noi (test_import_dbf 6, test_dashboard 5), suita 111 pass,
dry-run real pe DBF-urile din repo + smoke live dashboard/CSV.

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

app/web/templates/_nomenclator.html

@@ -0,0 +1,16 @@
+{% if rows %}
+<table>
+  <thead><tr><th>Cod</th><th>Denumire</th><th>Actualizat</th></tr></thead>
+  <tbody>
+  {% for r in rows %}
+    <tr>
+      <td><span class="pill">{{ r.cod_prestatie }}</span></td>
+      <td>{{ r.nume_prestatie }}</td>
+      <td class="muted">{{ r.updated_at }}</td>
+    </tr>
+  {% endfor %}
+  </tbody>
+</table>
+{% else %}
+<div class="empty">Nomenclator gol. Worker-ul il umple la primul login RAR reusit.</div>
+{% endif %}