feat(branding): add HealthChat launcher icon and logo

Official cross-in-circle icon (same art as the iOS X app); onboarding
title localized for en/de/fr/it.

app/build.gradle.kts

@@ -261,7 +261,7 @@ dependencies {
         implementation(projects.appicon.enterprise)
     } else {
         implementation(projects.features.enterprise.implFoss)
-        implementation(projects.appicon.element)
+        implementation(projects.appicon.healthchat)
     }
     allFeaturesImpl(project)
     implementation(projects.features.migration.api)

app/src/main/res/values-de/strings.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  ~ Copyright (c) 2026 Novaloop AG
+  ~
+  ~ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+  ~ Please see LICENSE files in the repository root for full details.
+  -->
+<resources>
+    <string name="screen_onboarding_welcome_title">"Willkommen bei HealthChat"</string>
+</resources>

app/src/main/res/values-fr/strings.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  ~ Copyright (c) 2026 Novaloop AG
+  ~
+  ~ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+  ~ Please see LICENSE files in the repository root for full details.
+  -->
+<resources>
+    <string name="screen_onboarding_welcome_title">"Bienvenue chez HealthChat"</string>
+</resources>

app/src/main/res/values-it/strings.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  ~ Copyright (c) 2026 Novaloop AG
+  ~
+  ~ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+  ~ Please see LICENSE files in the repository root for full details.
+  -->
+<resources>
+    <string name="screen_onboarding_welcome_title">"Benvenuto su HealthChat"</string>
+</resources>

app/src/main/res/values/strings.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  ~ Copyright (c) 2026 Novaloop AG
+  ~
+  ~ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+  ~ Please see LICENSE files in the repository root for full details.
+  -->
+<resources xmlns:tools="http://schemas.android.com/tools">
+    <!-- HealthChat override of the Element onboarding title ("Be in your element").
+         Overridden here app-side instead of editing the Localazy-managed login
+         strings, so upstream merges stay clean. Only the main HealthChat locales
+         are overridden; other locales fall back to their Element translation. -->
+    <string name="screen_onboarding_welcome_title" tools:ignore="MissingTranslation">"Welcome to HealthChat"</string>
+</resources>