feat: My Account — modifier username, nom, email, mot de passe

Backend:
- PUT /api/settings/account (full_name, login, email, password)
- Vérifie que le username n'est pas déjà pris
- Password min 6 caractères

Frontend (Settings → My Account):
- Champs éditables: Username, Full name, Email
- Section Change password avec toggle 👁/🙈
- Bouton Save changes + Update password
- Message de confirmation ✓ / ✗ avec timeout 3s

app/templates/settings.html

@@ -150,17 +150,47 @@
               </template>
             </div>
           </div>
-          <div class="setting-row">
-            <div>
-              <div class="setting-label">Full name</div>
-              <div class="setting-desc" x-text="userInfo.full_name || userInfo.login"></div>
+        </div>
+
+        <!-- Editable fields -->
+        <div class="setting-group">
+          <h3>Account details</h3>
+          <div class="setting-row" style="flex-direction:column;align-items:stretch;gap:4px;">
+            <div class="setting-label">Username</div>
+            <input type="text" class="settings-input" x-model="accountForm.login" style="max-width:300px;">
+          </div>
+          <div class="setting-row" style="flex-direction:column;align-items:stretch;gap:4px;">
+            <div class="setting-label">Full name</div>
+            <input type="text" class="settings-input" x-model="accountForm.full_name" style="max-width:300px;">
+          </div>
+          <div class="setting-row" style="flex-direction:column;align-items:stretch;gap:4px;">
+            <div class="setting-label">Email</div>
+            <input type="email" class="settings-input" x-model="accountForm.email" style="max-width:300px;">
+          </div>
+          <div style="margin-top:12px;">
+            <button class="btn btn-primary" @click="saveAccount()" :disabled="accountSaving" style="width:auto;padding:8px 20px;font-size:13px;">
+              <span x-show="!accountSaving">💾 Save changes</span>
+              <span x-show="accountSaving">Saving…</span>
+            </button>
+            <span x-show="accountMsg" x-text="accountMsg" style="margin-left:12px;font-size:13px;color:#0F7B6C;"></span>
+          </div>
+        </div>
+
+        <!-- Password change -->
+        <div class="setting-group">
+          <h3>Change password</h3>
+          <div class="setting-row" style="flex-direction:column;align-items:stretch;gap:4px;">
+            <div class="setting-label">New password</div>
+            <div class="pw-wrapper" style="max-width:300px;">
+              <input :type="pwVisible ? 'text' : 'password'" class="settings-input" x-model="accountForm.password" placeholder="Leave blank to keep current" style="padding-right:36px;">
+              <button type="button" class="pw-toggle" @click="pwVisible=!pwVisible" x-text="pwVisible ? '🙈' : '👁'" style="top:50%;"></button>
             </div>
           </div>
-          <div class="setting-row">
-            <div>
-              <div class="setting-label">Email</div>
-              <div class="setting-desc" x-text="userInfo.email || '—'"></div>
-            </div>
+          <div style="margin-top:12px;">
+            <button class="btn btn-primary" @click="saveAccount()" :disabled="accountSaving || !accountForm.password" style="width:auto;padding:8px 20px;font-size:13px;">
+              <span x-show="!accountSaving">🔒 Update password</span>
+              <span x-show="accountSaving">Saving…</span>
+            </button>
           </div>
         </div>
       </div>
@@ -472,6 +502,11 @@ document.addEventListener('alpine:init', function() {
       defaultView: localStorage.getItem('fd_default_view') || 'tree',
       userInfo: {full_name: '{{ user.full_name or "" }}', login: '{{ user.login or "" }}', email: '{{ user.email or "" }}'},
       userIsAdmin: {{ 'true' if user.get('is_admin') else 'false' }},
+      // Account form
+      accountForm: {login:'{{ user.login or "" }}', full_name:'{{ user.full_name or "" }}', email:'{{ user.email or "" }}', password:''},
+      accountSaving: false,
+      accountMsg: '',
+      pwVisible: false,
       // Admin data
       adminUsers: [],
       adminStats: {},
@@ -628,6 +663,34 @@ document.addEventListener('alpine:init', function() {
         } catch(e) {}
       },
 
+      async saveAccount() {
+        this.accountSaving = true;
+        this.accountMsg = '';
+        var body = {};
+        var f = this.accountForm;
+        if (f.full_name !== this.userInfo.full_name) body.full_name = f.full_name;
+        if (f.login !== this.userInfo.login) body.login = f.login;
+        if (f.email !== this.userInfo.email) body.email = f.email;
+        if (f.password) body.password = f.password;
+        if (Object.keys(body).length === 0) { this.accountSaving = false; return; }
+        try {
+          var r = await fetch('/api/settings/account', {
+            method: 'PUT', headers: {'Content-Type':'application/json', 'X-CSRF-Token': this.getCsrfToken()},
+            body: JSON.stringify(body)
+          });
+          var d = await r.json();
+          if (r.ok) {
+            this.userInfo = {login: d.user.login, full_name: d.user.full_name, email: d.user.email};
+            this.accountForm.password = '';
+            this.accountMsg = '✓ Saved!';
+            setTimeout(() => { this.accountMsg = ''; }, 3000);
+          } else {
+            this.accountMsg = '✗ ' + (d.error || 'Error');
+          }
+        } catch(e) { this.accountMsg = '✗ Network error'; }
+        this.accountSaving = false;
+      },
+
       async uploadAvatar(ev) {
         var file = ev.target.files[0];
         if (!file) return;