Correction des redirections

frontend/src/pages/InvestissementDetail.jsx

@@ -1,5 +1,5 @@
 import { useEffect, useRef, useState } from 'react';
-import { useNavigate, useParams, useSearchParams } from 'react-router-dom';
+import { useLocation, useNavigate, useParams, useSearchParams } from 'react-router-dom';
 import { api } from '../api.js';
 import { useInvestisseur } from '../context/InvestisseurContext.jsx';
 import { useUi } from '../context/UiContext.jsx';
@@ -103,6 +103,8 @@ function xirr(cashflows) {
 export default function InvestissementDetail() {
   const { id } = useParams();
   const navigate = useNavigate();
+  const location = useLocation();
+  const navOrigin = location.state?.from ?? null;
   const [searchParams, setSearchParams] = useSearchParams();
   const { activeId, investisseurs } = useInvestisseur();
   const { displayMode } = useUi();
@@ -806,8 +808,11 @@ export default function InvestissementDetail() {
           <span style={{ color: 'var(--text-muted, #6b7280)', fontWeight: 300, fontSize: '0.85em' }}>·</span>
           <span>{inv.nom_projet}</span>
         </h2>
-        <button onClick={() => navigate('/investissements')} style={{ whiteSpace: 'nowrap', flexShrink: 0 }}>
-          ← Investissements
+        <button
+          onClick={() => navOrigin ? navigate({ pathname: navOrigin.path, search: navOrigin.search || '' }) : navigate('/investissements')}
+          style={{ whiteSpace: 'nowrap', flexShrink: 0 }}
+        >
+          ← {navOrigin?.label ?? 'Investissements'}
         </button>
       </div>