Add branding configuration and assets for Sepehr tenant

- Created branding.config.ts to define branding settings including app title, support contact information, and working hours.
- Added brandingAssets.ts to import and export logo and login images for the Sepehr tenant.
- Introduced config.ts to specify application type as POS for the Sepehr tenant.

src/app/modules/auth/pages/auth.component.html

@@ -1,14 +1,13 @@
-<div class="bg-white h-svh relative">
-  <div class="absolute inset-0 opacity-30 blur-xs flex items-center justify-center">
+<div class="relative h-svh bg-white">
+  <div class="absolute inset-0 flex items-center justify-center opacity-30 blur-xs">
     <img [src]="authVector" alt="background image" class="w-full bg-cover bg-no-repeat" />
   </div>
-  <div class="flex justify-center items-center relative z-10 h-svh mx-auto bg-gray-800/80">
+  <div class="relative z-10 mx-auto flex h-svh items-center justify-center bg-gray-800/80">
     <div
-      class="flex flex-col items-center justify-center px-12 py-10 h-auto bg-surface-card border border-surface-border rounded-lg shadow w-full max-w-md"
-    >
-      <div class="flex flex-col gap-4 text-center mb-10 items-center justify-center">
-        <img [src]="logo" alt="مدیریت صورت‌حساب‌های مالیاتی" class="w-20 h-auto" />
-        <span class="text-lg font-bold"> به پنل مدیریت صورت‌حساب‌های مالیاتی پاژن خوش آمدید. </span>
+      class="bg-surface-card border-surface-border flex h-auto w-full max-w-md flex-col items-center justify-center rounded-lg border px-12 py-10 shadow">
+      <div class="mb-10 flex flex-col items-center justify-center gap-4 text-center">
+        <img [src]="logo" alt="مدیریت صورت‌حساب‌های مالیاتی" class="h-auto w-20" />
+        <span class="text-lg font-bold"> به پنل مدیریت صورت‌حساب‌های مالیاتی سپاس خوش آمدید. </span>
       </div>
 
       <!-- @if (activeStep() === "login") { -->
@@ -18,8 +17,7 @@
         [defaultRole]="role"
         class="w-full"
         (onSuccessfullySubmit)="onLoggedIn($event)"
-        (onToSignup)="toSignUp()"
-      />
+        (onToSignup)="toSignUp()" />
       <!-- } @else if (activeStep() === "signup") {
         <auth-signup role="TEACHER" class="w-full" />
       } @else if (activeStep() === "otp") {