[backend/frontend] Login aside panel customization (#14115)

Author: esrevi

docs/docs/administration/assets/theme-desc-1.png

@@ -87,9 +87,9 @@ Click on the **+** icon and configure your theme properties.
 | **Name**              | Unique identifier for the theme (case-sensitive)                                                      | Theme selector                                        | `My Theme`    |
 | **Background color**  | Main application background                                                                           | Behind all content areas                              | `#122e52`     |
 | **Paper color**       | Background for content containers                                                                     | Cards, side panels, dialog bodies                     | `#0a395f`     |
-| **Navigation color**  | Navigation and header elements                                                                        | Top app bar, dialog headers, right navigation panels  | `#060b3f`     |
+| **Navigation color**  | Navigation and header elements                                                                        | Dialog headers, right navigation panels  | `#060b3f`     |
 | **Primary color**     | Main interactive elements                                                                             | Icon buttons, action buttons, highlights | `#e41682`  |
-| **Secondary color**   | Secondary actions                                                                                     | Primary action buttons in dialogs                     | `#d1c71d`     |
+| **Secondary color**   | Secondary actions                                                                                     | Badge color                     | `#d1c71d`     |
 | **Accent color**      | Highlight and emphasis                                                                                | Copied items, history entries, selected items         | `#e5abec`     |
 | **Text color**        | Primary text throughout the application                                                               | All text content                                      | `#e0e0e0`     |
 | **Logo URL**          | Full-size logo                                                                                        | Expanded left navigation panel                        | URL or Base64 |
@@ -101,6 +101,28 @@ Click on the **+** icon and configure your theme properties.
 
 ![Theme Colors in Dialog](assets/theme-desc-1.png)
 
+![Theme Colors in Parameters](assets/theme-desc-3.png)
+
+#### Login aside customization
+
+The right panel of the login page can be customized with three options:
+
+- **Color**: a single solid background color
+- **Gradient**: a linear gradient between two colors applied horizontally from the start color to the end color
+- **Image**: full-cover background image via URL or Base64. The image is scaled to cover the entire panel and centered, so edges may be cropped on smaller screens. Prefer images with a centered subject.
+
+![Login Aside config](assets/theme-login-aside-config.png)
+
+
+![Login Aside default](assets/theme-login-1.png)
+*Login page with no aside config set*
+
+![Login Aside with gradient](assets/theme-login-2.png)
+*Login page with a custom gradient background*
+
+
+
+
 #### Color requirements
 - **Format:** All colors must be in hexadecimal format (e.g., `#122e52`)
 - **Contrast:** Ensure adequate contrast between text and background colors for accessibility

docs/docs/administration/assets/theme-desc-2.png

@@ -954,6 +954,10 @@
   "Theme": "Thema",
   "Theme accent": "Thema Akzent",
   "Theme background": "Thema Hintergrund",
+  "Theme login aside color": "Thema Anmeldung neben Farbe",
+  "Theme login aside gradient end": "Theme login aside gradient end",
+  "Theme login aside gradient start": "Thema login aside gradient start",
+  "Theme login aside image": "Thema login aside Bild",
   "Theme logo": "Thema Logo",
   "Theme logo collapsed": "Theme-Logo kollabiert",
   "Theme logo login": "Themenlogo Anmeldung",

docs/docs/administration/assets/theme-desc-3.png

@@ -954,6 +954,10 @@
   "Theme": "Theme",
   "Theme accent": "Theme accent",
   "Theme background": "Theme background",
+  "Theme login aside color": "Theme login aside color",
+  "Theme login aside gradient end": "Theme login aside gradient end",
+  "Theme login aside gradient start": "Theme login aside gradient start",
+  "Theme login aside image": "Theme login aside image",
   "Theme logo": "Theme logo",
   "Theme logo collapsed": "Theme logo collapsed",
   "Theme logo login": "Theme logo login",

docs/docs/administration/assets/theme-login-1.png

@@ -954,6 +954,10 @@
   "Theme": "Tema",
   "Theme accent": "Acento temático",
   "Theme background": "Tema de fondo",
+  "Theme login aside color": "Tema login aparte color",
+  "Theme login aside gradient end": "Tema login aside gradient end",
+  "Theme login aside gradient start": "Inicio de degradado del tema de inicio de sesión",
+  "Theme login aside image": "Imagen de inicio de sesión",
   "Theme logo": "Tema logotipo",
   "Theme logo collapsed": "Logotipo del tema colapsado",
   "Theme logo login": "Inicio de sesión del logotipo del tema",