style(auth): update form placeholders to french localization

src/features/auth/pages/ForgotPasswordPage.client.js

@@ -99,7 +99,7 @@ export default function ForgotPasswordPage({ onSubmit, onNavigate, currentUser =
           label="E-mail"
           value={email}
           onChange={setEmail}
-          placeholder="your@email.com"
+          placeholder="votre@courriel.com"
           disabled={!!success || !!currentUser}
           autoComplete="email"
           required

src/features/auth/pages/LoginPage.client.js

@@ -117,7 +117,7 @@ export default function LoginPage({ onSubmit, onNavigate, onSetSessionCookie, re
           value={formData.email}
           onChange={(value) => setFormData(prev => ({ ...prev, email: value }))}
           onKeyDown={handleKeyPress}
-          placeholder="your@email.com"
+          placeholder="votre@courriel.com"
           disabled={!!success || !!currentUser}
           required
         />

src/features/auth/pages/RegisterPage.client.js

@@ -151,7 +151,7 @@ export default function RegisterPage({ onSubmit, onNavigate, currentUser = null
           label="Nom complet"
           value={formData.name}
           onChange={(value) => setFormData(prev => ({ ...prev, name: value }))}
-          placeholder="John Doe"
+          placeholder="Lou Doe"
           disabled={!!success || !!currentUser}
           maxLength="100"
           autoComplete="name"
@@ -165,7 +165,7 @@ export default function RegisterPage({ onSubmit, onNavigate, currentUser = null
           label="E-mail"
           value={formData.email}
           onChange={(value) => setFormData(prev => ({ ...prev, email: value }))}
-          placeholder="your@email.com"
+          placeholder="votre@courriel.com"
           disabled={!!success || !!currentUser}
           maxLength="254"
           autoComplete="email"