Let admins create and delete users in Benutzerverwaltung, modernize list

Wire up two previously-unwired stored procedures for the usr module:
- fis_admin_createUserAccount gained the missing @authaccount +
  intranet_admin auth gate, a duplicate-email check, and now returns
  the (possibly auto-generated) password so it can be emailed to the
  new user, mirroring fis_admin_resetUserPassword's pattern.
- fis_admin_delUserAccount gained the same missing auth gate plus a
  guard against an admin deleting their own account.

New /do/usr/create and /do/usr/delete endpoints in
IntranetController.AdminUsers.cs, a "Neuer Benutzer" button and a
"Benutzer löschen" ribbon action in fis.usr.js, and unit tests for the
new welcome-email content (BuildWelcomeEmail).

Also restyle the user list (fis.usr.scss) from a plain bordered table
to a card-style row grid with avatar-initial badges and status pills,
matching the Admin dashboard's visual language.

Documented as ADR 0020 and in the admin-user-management concept doc.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Fuchs_Database/dbo/Stored Procedures/fis_admin_createUserAccount.sql

@@ -7,7 +7,8 @@
 -- Description:	<Description, ,>
 -- =============================================
 CREATE PROCEDURE [dbo].[fis_admin_createUserAccount]
-	@name nvarchar(100)
+	@authaccount varchar(5)
+	,@name nvarchar(100)
 	,@firstname nvarchar(100)
 	,@title varchar(50)
 	,@gender varchar(1)
@@ -20,41 +21,59 @@ BEGIN
 	SET NOCOUNT ON;
 
     DECLARE @utcnow datetime = GETUTCDATE();
+	DECLARE @auth smallint = [dbo].[fis_admin_getUserAuth](@authaccount);
+	DECLARE @newid varchar(5);
 
-	INSERT INTO [dbo].[fis_useraccounts]
-           ([useraccount_id]
-           ,[name_enc]
-		   ,[firstname_enc]
-		   ,[title_enc]
-		   ,[gender_enc]
-           ,[email_enc]
-           ,[mobile_enc]
-           ,[password_enc]
-           ,[UserDisabled]
-           ,[DateDisabled]
-           ,[UserCreated]
-           ,[DateCreated]
-           ,[UserModified]
-           ,[DateModified]
-           ,[UserDeleted]
-           ,[DateDeleted])
-	 OUTPUT inserted.[useraccount_id]
-     VALUES
-           ([dbo].[fis_fn_useraccount_id] ()
-           ,ENCRYPTBYKEY(@enc_key, @name)
-		   ,ENCRYPTBYKEY(@enc_key, @firstname)
-		   ,ENCRYPTBYKEY(@enc_key, @title)
-		   ,ENCRYPTBYKEY(@enc_key, @gender)
-           ,ENCRYPTBYKEY(@enc_key, @email)
-           ,ENCRYPTBYKEY(@enc_key, @mobile)
-           ,CASE WHEN @password is null then ENCRYPTBYKEY(@enc_key, CAST([dbo].[ocms_fn_generatePassword] (8, 0, 1, 1) AS nvarchar(20))) ELSE ENCRYPTBYKEY(@enc_key, @password) END
-           ,NULL  --[UserDisabled]
-           ,NULL  --[DateDisabled]
-           ,'sa'
-           ,@utcnow
-           ,'sa'
-           ,@utcnow
-           ,NULL
-           ,NULL);
+	IF @auth > 1
+	BEGIN
+
+		IF EXISTS (SELECT * FROM [dbo].[fis_useraccounts] WHERE [DateDeleted] is null AND ISNULL(@email,'') <> '' AND LTRIM(RTRIM(DECRYPTBYKEY([email_enc]))) like LTRIM(RTRIM(@email)))
+			THROW 60001, 'email is already assigned to another account', 1;
+
+		IF @password IS NULL
+		BEGIN
+			SET @password = [dbo].[ocms_fn_generatePassword] (8, 0, 1, 1);
+		END
+
+		SET @newid = [dbo].[fis_fn_useraccount_id] ();
+
+		INSERT INTO [dbo].[fis_useraccounts]
+			   ([useraccount_id]
+			   ,[name_enc]
+			   ,[firstname_enc]
+			   ,[title_enc]
+			   ,[gender_enc]
+			   ,[email_enc]
+			   ,[mobile_enc]
+			   ,[password_enc]
+			   ,[UserDisabled]
+			   ,[DateDisabled]
+			   ,[UserCreated]
+			   ,[DateCreated]
+			   ,[UserModified]
+			   ,[DateModified]
+			   ,[UserDeleted]
+			   ,[DateDeleted])
+		 VALUES
+			   (@newid
+			   ,ENCRYPTBYKEY(@enc_key, @name)
+			   ,ENCRYPTBYKEY(@enc_key, @firstname)
+			   ,ENCRYPTBYKEY(@enc_key, @title)
+			   ,ENCRYPTBYKEY(@enc_key, @gender)
+			   ,ENCRYPTBYKEY(@enc_key, @email)
+			   ,ENCRYPTBYKEY(@enc_key, @mobile)
+			   ,ENCRYPTBYKEY(@enc_key, @password)
+			   ,NULL  --[UserDisabled]
+			   ,NULL  --[DateDisabled]
+			   ,@authaccount
+			   ,@utcnow
+			   ,@authaccount
+			   ,@utcnow
+			   ,NULL
+			   ,NULL);
+
+		SELECT TOP(1) *, @password as [newpassword] FROM [dbo].[fis_admin_getUserAccountList](@authaccount, @newid, null, null);
+
+	END
 
 END