[FEAT] Dashboard: card Documenti istituzionali funzionante + UI (ticket #499)

- loadDocs: 5 voci standard sempre presenti + voci custom + 'Aggiungi voce'
- modale add/edit con descrizione OBBLIGATORIA (richiesta punto 1), link doc opzionale
- delete voci custom; controlli visibili a org_admin/compliance_manager/super_admin
- CSS .doc-* in v3.css; cache-buster dashboard.js/v3.css su dashboard.html; version 1.25.1

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

public/css/v3.css

@@ -302,6 +302,17 @@ a.stat:hover{box-shadow:0 8px 20px rgba(16,40,80,.13);transform:translateY(-1px)
 .btn-outline:hover:not(:disabled){background:var(--navy-nav);color:#fff}
 .btn-secondary:disabled,.btn-success:disabled,.btn-danger:disabled,.btn-warning:disabled,.btn-outline:disabled{opacity:.5;cursor:not-allowed}
 .btn-sm{padding:6px 14px;font-size:.8rem}
+/* Documenti istituzionali (dashboard) — ticket #499 */
+.doc-list{display:flex;flex-direction:column;gap:2px}
+.doc-item{display:flex;align-items:flex-start;justify-content:space-between;gap:10px;padding:10px 4px;border-bottom:1px solid var(--v3-border,#e6e8ee)}
+.doc-item:last-of-type{border-bottom:none}
+.doc-main{display:flex;flex-direction:column;gap:2px;min-width:0}
+.doc-main b{font-size:.92rem}
+.doc-desc{font-size:.82rem;color:var(--v3-muted,#5b6472);white-space:pre-line;word-break:break-word}
+.doc-empty-desc{font-style:italic;opacity:.75}
+.doc-file{font-size:.78rem;font-weight:500;margin-left:6px}
+.doc-actions{display:flex;gap:2px;flex:0 0 auto}
+.doc-add{margin-top:8px}
 .btn-lg{padding:14px 28px;font-size:1rem}
 .btn-icon{padding:8px;width:36px;height:36px}
 .btn-group{display:flex;gap:8px}