Update login screen and site settings with editable footer and AI art

Add editable footer text fields to site settings, update OpenAPI schema and API client, refactor the login page to display AI-generated artwork and use dynamic footer text, and remove the old logo and welcome heading.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 77cfe984-2c65-4152-bb7a-0df28274fe66
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Event-Id: a650b496-7c3c-427e-bfbe-77bc8b9b5dd2
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/c3c252e4-c83d-40ca-9fff-99a3ea60701e/77cfe984-2c65-4152-bb7a-0df28274fe66/gdgNDb6
Replit-Helium-Checkpoint-Created: true

lib/api-spec/openapi.yaml

@@ -1219,7 +1219,7 @@ components:
 
     AppSettings:
       type: object
-      required: [siteNameAr, siteNameEn, registrationOpen]
+      required: [siteNameAr, siteNameEn, registrationOpen, footerTextAr, footerTextEn]
       properties:
         siteNameAr:
           type: string
@@ -1227,6 +1227,10 @@ components:
           type: string
         registrationOpen:
           type: boolean
+        footerTextAr:
+          type: string
+        footerTextEn:
+          type: string
         updatedAt:
           type: string
           format: date-time
@@ -1254,6 +1258,14 @@ components:
           maxLength: 200
         registrationOpen:
           type: boolean
+        footerTextAr:
+          type: string
+          minLength: 1
+          maxLength: 300
+        footerTextEn:
+          type: string
+          minLength: 1
+          maxLength: 300
 
     RequestUploadUrlBody:
       type: object