Add rejection retry flow with configurable wait days

- Backend: DELETE /professionals/me resets rejected state so user can retry
- Backend: findRejected/findPending now filter by pro_state
- Admin settings: rejection_wait_days field (default 7)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

admin/src/app/settings/page.tsx

@@ -263,6 +263,32 @@ export default function SettingsPage() {
           </CardContent>
         </Card>
 
+        {/* Solicitudes de profesional */}
+        <Card>
+          <CardHeader>
+            <CardTitle className="flex items-center gap-2 text-base">
+              <Clock size={18} className="text-muted-foreground" />
+              Solicitudes de profesional
+            </CardTitle>
+          </CardHeader>
+          <CardContent>
+            <div className="space-y-1">
+              <label className="text-sm text-muted-foreground">Días de espera para reintentar tras rechazo</label>
+              <div className="flex items-center gap-2">
+                <Input
+                  type="number"
+                  min={0}
+                  className="w-28"
+                  value={global.rejection_wait_days ?? 7}
+                  onChange={(e) => setG('rejection_wait_days', Number(e.target.value))}
+                />
+                <span className="text-sm text-muted-foreground">días</span>
+              </div>
+              <p className="text-xs text-muted-foreground">Con 0 el usuario puede reintentar inmediatamente.</p>
+            </div>
+          </CardContent>
+        </Card>
+
         <Button onClick={saveGlobal} disabled={savingGlobal}>
           <Save className="mr-1 h-4 w-4" />
           {savingGlobal ? 'Guardando...' : 'Guardar ajustes generales'}