fix(frontend): logo/favicon corrects et pages d'authentification plus posees

Le src="logo.png" relatif resolvait mal sur les routes autres que "/" :
chemin absolu "/logo.png". Titre de page "Frontend" -> "EnerVision", favicon
regenere depuis l'icone reelle du logo. Pages login/change-password
retravaillees (fond degrade de marque, carte plus large, logo et titre plus
presents) via une classe .auth-page partagee plutot que dupliquee par page.

apps/frontend/src/app/features/auth/change-password/change-password.html

@@ -1,7 +1,7 @@
 <div class="auth-page">
   <form class="auth-card-wrapper" [formGroup]="form" (ngSubmit)="onSubmit()">
     <ev-card>
-      <img src="logo.png" alt="EnerVision" class="auth-logo" />
+      <img src="/logo.png" alt="EnerVision" class="auth-logo" />
       <h1>Nouveau mot de passe</h1>
       <p class="auth-subtitle">Votre mot de passe est provisoire, vous devez le modifier avant de continuer</p>
 

apps/frontend/src/app/features/auth/change-password/change-password.scss

@@ -1,34 +1,28 @@
-:host {
-  display: flex;
-  align-items: center;
-  justify-content: center;
-  min-height: 100vh;
-  background: var(--color-bg);
-}
-
-.auth-card-wrapper {
-  width: 100%;
-  max-width: 360px;
+ev-card {
+  padding: 3rem 2.5rem;
+  box-shadow:
+    0 20px 25px -5px rgba(0, 0, 0, 0.06),
+    0 8px 10px -6px rgba(0, 0, 0, 0.04);
 }
 
 .auth-logo {
   display: block;
-  height: 48px;
-  margin: 0 auto 1rem;
+  height: 64px;
+  margin: 0 auto 1.5rem;
 }
 
 h1 {
   margin: 0;
-  font-size: 1.5rem;
+  font-size: 1.85rem;
   font-weight: 700;
   color: var(--color-text);
   text-align: center;
 }
 
 .auth-subtitle {
-  margin: 0.25rem 0 1.5rem;
+  margin: 0.4rem 0 2rem;
   color: var(--color-text-muted);
-  font-size: 0.9rem;
+  font-size: 0.95rem;
   line-height: 1.4;
   text-align: center;
 }
@@ -40,5 +34,5 @@ ev-alert {
 
 ev-button {
   display: block;
-  margin-top: 1.5rem;
+  margin-top: 1.75rem;
 }

apps/frontend/src/app/features/auth/login/login.html

@@ -1,7 +1,7 @@
 <div class="auth-page">
   <form class="auth-card-wrapper" [formGroup]="form" (ngSubmit)="onSubmit()">
     <ev-card>
-      <img src="logo.png" alt="EnerVision" class="auth-logo" />
+      <img src="/logo.png" alt="EnerVision" class="auth-logo" />
       <h1>Connexion</h1>
       <p class="auth-subtitle">Accédez à votre espace EnerVision</p>
 

apps/frontend/src/app/features/auth/login/login.scss

@@ -1,34 +1,28 @@
-:host {
-  display: flex;
-  align-items: center;
-  justify-content: center;
-  min-height: 100vh;
-  background: var(--color-bg);
-}
-
-.auth-card-wrapper {
-  width: 100%;
-  max-width: 360px;
+ev-card {
+  padding: 3rem 2.5rem;
+  box-shadow:
+    0 20px 25px -5px rgba(0, 0, 0, 0.06),
+    0 8px 10px -6px rgba(0, 0, 0, 0.04);
 }
 
 .auth-logo {
   display: block;
-  height: 48px;
-  margin: 0 auto 1rem;
+  height: 64px;
+  margin: 0 auto 1.5rem;
 }
 
 h1 {
   margin: 0;
-  font-size: 1.5rem;
+  font-size: 1.85rem;
   font-weight: 700;
   color: var(--color-text);
   text-align: center;
 }
 
 .auth-subtitle {
-  margin: 0.25rem 0 1.5rem;
+  margin: 0.4rem 0 2rem;
   color: var(--color-text-muted);
-  font-size: 0.9rem;
+  font-size: 0.95rem;
   text-align: center;
 }
 
@@ -39,5 +33,5 @@ ev-alert {
 
 ev-button {
   display: block;
-  margin-top: 1.5rem;
+  margin-top: 1.75rem;
 }