feat(web): dashboard ergonomic cu tab-uri, stepper import si microcopy uman (3.4)

Reorganizeaza interfata web pe trei principii, fara a atinge backend-ul de
trimitere (worker, mapping, idempotency, masina de stari neatinse):

- US-001 app/web/labels.py: modul pur stari tehnice -> text uman + clasa CSS
- US-002 bara status /_fragments/status: microcopy uman, defalcare blocate, scoped cont
- US-003 shell 6 tab-uri (Acasa/Import/Coada/Mapari/Cont/Nomenclator): deep-link
  ?tab=, panou activ randat server-side, fragmente inactive lazy, ARIA real
- US-004 stepper import 4 pasi (pur vizual; hx-target + csrf pastrate)
- US-005 Acasa onboarding checklist auto-bifat + colaps + empty states prietenoase

Reparat in cursul VERIFY/CLOSE: izolare teste (reset ratelimit._hits in fixturi),
regresie avertisment "cont in asteptare de activare" (re-introdus in bara status),
culori hardcodate -> variabile paleta. 434 teste pass.

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

app/web/templates/_mapari.html

@@ -6,7 +6,10 @@
   {% endif %}
 
   {% if not pending %}
-  <div class="empty">Nicio operatie nemapata. Tot ce a venit s-a tradus in coduri RAR.</div>
+  <div class="empty">
+    Nicio operatie nemapata — tot ce a venit s-a tradus in coduri RAR.
+    <a href="/?tab=import">Importa un fisier nou</a> daca vrei sa adaugi prezentari.
+  </div>
   {% else %}
   <p class="muted" style="margin:0 0 12px; font-size:13px;">
     Operatii ROAAUTO necunoscute, blocate in <span class="s-needs_mapping">needs_mapping</span>.