Redesign login UI, add theme toggle, refactor user update

- Redesigned login page with two-panel layout and branding
- Added HexaDistro logo and theme toggle to sidebar/header
- Refactored user update: roles via update endpoint, removed assignRole API/controller
- Extended UpdateUserRequest for username, role, password changes
- UserService.UpdateAsync syncs changes with AuthHex, with rollback
- Stock balances client dedupes by itemId-locationId
- Middleware matcher excludes static assets from auth checks
- Improved localStorage clearing for user context
- Added lucide-react for icons
- Minor UI/code cleanups for consistency and UX

Distribution/Features/User/UserController.cs

@@ -31,13 +31,6 @@ public class UserController(UserService service) : ControllerBase
         return result is null ? NotFound() : Ok(result);
     }
 
-    [HttpPut("{id:guid}/role")]
-    public async Task<IActionResult> AssignRole(Guid id, AssignUserRoleRequest request, CancellationToken ct)
-    {
-        var result = await service.AssignRoleAsync(id, request, ct);
-        return result is null ? NotFound() : Ok(result);
-    }
-
     [HttpPut("{id:guid}/scope")]
     public async Task<IActionResult> AssignScope(Guid id, AssignUserScopeRequest request, CancellationToken ct)
     {