feat: rebrand AgendaPro -> AgendaMax + calendar fixes + current-week demo seed

- Rebrand all user-facing text to AgendaMax
- Fix sidebar scrolling: card container no longer overflows html (flex h-full min-h-0)
- Fix calendar toolbar hover: active buttons keep readable contrast
- Sticky calendar toolbar (month/week/day always visible on scroll)
- Seed guarantees 2-4 appointments per day for current week (Mon-Sat)

src/pages/EmployeesPage.tsx

@@ -130,9 +130,9 @@ export function EmployeesPage() {
                 )}
                 <div className="mt-3 flex items-center gap-2 text-[11px] text-slate-400">
                   <Activity className="h-3 w-3" />
-                  Utilización {e.stats?.utilization_pct ?? 0}%
+                  % de citas {e.stats?.share_pct ?? 0}%
                   <div className="ml-1 h-1.5 flex-1 overflow-hidden rounded-full bg-slate-100">
-                    <div className="h-full rounded-full bg-brand-500" style={{ width: `${e.stats?.utilization_pct ?? 0}%` }} />
+                    <div className="h-full rounded-full bg-brand-500" style={{ width: `${e.stats?.share_pct ?? 0}%` }} />
                   </div>
                 </div>
               </div>