feat(5.12): modal editare + cont obligatoriu la import; design.md + PRD 5.13 revizuit (/autoplan)

5.12 (livrat): editare in modal a randurilor de preview, cont obligatoriu inainte de
import, formular editare extras (_form_editare, _editare_preview_modal), plus suita de
teste aferenta (preview edit/compact, mapare op, form editare, signup, admin panel).

Design + planificare:
- docs/design.md: sistem de design (tokeni, breakpoints, scara control, componente, a11y).
- docs/prd/prd-5.12-* si prd-5.13-* (5.13 cu raport /autoplan: CEO+Design+Eng, audit trail).

Curatare: sterse PNG-urile de test/mockup temporare din radacina.

Nota: implementarea CSS 5.13 (responsive compact + sistem butoane) NU e inca facuta —
planul revizuit cere refactorul testelor fragile din test_web_responsive.py INAINTE de CSS.

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

tests/test_import_mapare_operatie.py

@@ -143,7 +143,8 @@ def test_preview_arata_panoul_de_mapare(client):
     assert r.status_code == 200
     assert "Operatii de mapat la cod RAR" in r.text
     assert "OP-REV" in r.text
-    assert "/_import/%d/mapare-operatie" % import_id in r.text
+    # US-004: panoul foloseste ruta plurala (un singur form pentru toate operatiile)
+    assert "/_import/%d/mapare-operatii" % import_id in r.text
 
 
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