Implement password prompt UI and logic in MultiChatDialog: Add a password entry panel with validation and error handling for room access. Update i18n files for localized password prompts in English, German, and Spanish.

frontend/src/dialogues/chat/MultiChatDialog.vue

@@ -172,6 +172,23 @@
                     </div>
                 </div>
             </div>
+            <div v-if="!showColorPicker && passwordPromptVisible" class="room-password-panel">
+                <div class="room-password-title">{{ $t('chat.multichat.password.title') }}</div>
+                <div class="room-password-message">
+                    {{ passwordPromptInvalid ? $t('chat.multichat.password.invalidPrompt', { room: passwordPromptRoom }) : $t('chat.multichat.password.requiredPrompt', { room: passwordPromptRoom }) }}
+                </div>
+                <div class="room-password-controls">
+                    <input
+                        v-model="passwordPromptValue"
+                        class="room-password-input"
+                        type="password"
+                        :placeholder="$t('chat.multichat.password.inputLabel')"
+                        @keyup.enter="submitRoomPassword"
+                    />
+                    <button type="button" class="send-btn" @click="submitRoomPassword">{{ $t('chat.multichat.password.submit') }}</button>
+                    <button type="button" class="create-room-reset-btn" @click="cancelRoomPassword">{{ $t('chat.multichat.password.cancel') }}</button>
+                </div>
+            </div>
             <div v-if="!showColorPicker" class="multi-chat-input">
                 <input v-model="input" @keyup.enter="sendMessage" class="chat-input"
                     :placeholder="$t('chat.multichat.placeholder')" />
@@ -322,7 +339,10 @@ export default {
             pendingRoomCreateAttempts: 0,
             pendingRoomCreateTimer: null,
             roomPasswords: {},
-            passwordPromptActive: false,
+            passwordPromptVisible: false,
+            passwordPromptInvalid: false,
+            passwordPromptRoom: '',
+            passwordPromptValue: '',
             // Palette state
             paletteWidth: 420,
             paletteHeight: 220,
@@ -371,6 +391,10 @@ export default {
                 this.messages = [];
                 this.usersInRoom = [];
                 this.selectedTargetUser = null;
+                this.passwordPromptVisible = false;
+                this.passwordPromptInvalid = false;
+                this.passwordPromptRoom = '';
+                this.passwordPromptValue = '';
             }
         }
     },
@@ -411,38 +435,47 @@ export default {
             if (!roomName) return '';
             return this.roomPasswords[roomName] || '';
         },
-        async handleRoomPasswordError(errorCode) {
+        handleRoomPasswordError(errorCode) {
             const room = this.getSelectedRoomName();
-            if (!room || this.passwordPromptActive) return;
+            if (!room || this.passwordPromptVisible) return;
-            this.passwordPromptActive = true;
+            this.passwordPromptRoom = room;
-            try {
+            this.passwordPromptInvalid = errorCode === 'room_password_invalid';
-                const isInvalid = errorCode === 'room_password_invalid';
+            this.passwordPromptValue = '';
-                const promptText = isInvalid
+            this.passwordPromptVisible = true;
-                    ? this.$t('chat.multichat.password.invalidPrompt', { room })
+        },
-                    : this.$t('chat.multichat.password.requiredPrompt', { room });
+        submitRoomPassword() {
-                const entered = window.prompt(promptText, '');
+            const room = this.passwordPromptRoom || this.getSelectedRoomName();
-                if (entered === null) {
+            if (!room) {
-                    this.messages.push({
+                this.passwordPromptVisible = false;
-                        id: Date.now(),
+                return;
-                        user: 'System',
-                        text: this.$t('chat.multichat.password.cancelled', { room })
-                    });
-                    return;
-                }
-                const password = entered.trim();
-                if (!password) {
-                    this.messages.push({
-                        id: Date.now(),
-                        user: 'System',
-                        text: this.$t('chat.multichat.password.empty')
-                    });
-                    return;
-                }
-                this.roomPasswords[room] = password;
-                this.sendWithToken({ type: 'join', room, password });
-            } finally {
-                this.passwordPromptActive = false;
             }
+            const password = (this.passwordPromptValue || '').trim();
+            if (!password) {
+                this.messages.push({
+                    id: Date.now(),
+                    user: 'System',
+                    text: this.$t('chat.multichat.password.empty')
+                });
+                return;
+            }
+            this.roomPasswords[room] = password;
+            this.passwordPromptVisible = false;
+            this.passwordPromptInvalid = false;
+            this.passwordPromptRoom = '';
+            this.passwordPromptValue = '';
+            this.sendWithToken({ type: 'join', room, password });
+        },
+        cancelRoomPassword() {
+            const room = this.passwordPromptRoom || this.getSelectedRoomName();
+            this.passwordPromptVisible = false;
+            this.passwordPromptInvalid = false;
+            this.passwordPromptRoom = '';
+            this.passwordPromptValue = '';
+            this.messages.push({
+                id: Date.now(),
+                user: 'System',
+                text: this.$t('chat.multichat.password.cancelled', { room })
+            });
         },
         tryConfirmRoomCreateSuccess() {
             if (!this.pendingRoomCreateName) return false;
@@ -2162,6 +2195,40 @@ export default {
     margin-top: 0.5em;
 }
 
+.room-password-panel {
+    margin-top: 0.6em;
+    margin-bottom: 0.6em;
+    padding: 0.6em;
+    border: 1px solid #d7d7d7;
+    border-radius: 6px;
+    background: #f8f9fb;
+}
+
+.room-password-title {
+    font-weight: bold;
+    margin-bottom: 0.25em;
+}
+
+.room-password-message {
+    font-size: 0.9em;
+    color: #444;
+    margin-bottom: 0.45em;
+}
+
+.room-password-controls {
+    display: flex;
+    align-items: center;
+    gap: 0.45em;
+}
+
+.room-password-input {
+    flex: 1;
+    min-width: 0;
+    border: 1px solid #bbb;
+    border-radius: 3px;
+    padding: 0.35em 0.5em;
+}
+
 .chat-message {
     margin-bottom: 0.3em;
 }

frontend/src/i18n/locales/de/chat.json

@@ -116,6 +116,10 @@
                 "types": {}
             },
             "password": {
+                "title": "Passwort erforderlich",
+                "inputLabel": "Passwort eingeben",
+                "submit": "Beitreten",
+                "cancel": "Abbrechen",
                 "requiredPrompt": "Der Raum \"{room}\" ist passwortgeschützt. Bitte Passwort eingeben:",
                 "invalidPrompt": "Falsches Passwort für \"{room}\". Bitte erneut eingeben:",
                 "cancelled": "Beitritt zu \"{room}\" abgebrochen.",

frontend/src/i18n/locales/en/chat.json

@@ -116,6 +116,10 @@
                 "types": {}
             },
             "password": {
+                "title": "Password required",
+                "inputLabel": "Enter password",
+                "submit": "Join room",
+                "cancel": "Cancel",
                 "requiredPrompt": "Room \"{room}\" is password-protected. Please enter password:",
                 "invalidPrompt": "Wrong password for \"{room}\". Please try again:",
                 "cancelled": "Join to \"{room}\" was cancelled.",

frontend/src/i18n/locales/es/chat.json

@@ -115,6 +115,10 @@
                 "types": {}
             },
             "password": {
+                "title": "Contraseña requerida",
+                "inputLabel": "Introduce la contraseña",
+                "submit": "Entrar en sala",
+                "cancel": "Cancelar",
                 "requiredPrompt": "La sala \"{room}\" está protegida por contraseña. Introduce la contraseña:",
                 "invalidPrompt": "Contraseña incorrecta para \"{room}\". Inténtalo de nuevo:",
                 "cancelled": "Se canceló el acceso a \"{room}\".",