#3888 Fix 4 compatibility issues from Copilot review

- sp_BlitzWho: Add SQL Server 2016 SP2+ minimum build check (build 5026)
- sp_BlitzCache: Check compat level 130+ up front for STRING_SPLIT support
- sp_kill: Remove USE statement for Azure SQL DB compatibility, use 3-part naming
- sp_BlitzIndex: Update help text to say "2014 and older" instead of "2005 and 2000"

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: BrentOzar

sp_BlitzCache.sql

@@ -828,6 +828,13 @@ BEGIN
 	RETURN;
 END;
 
+/* Check database compatibility level for STRING_SPLIT support */
+IF (SELECT compatibility_level FROM sys.databases WHERE database_id = DB_ID()) < 130
+BEGIN
+    RAISERROR('sp_BlitzCache requires database compatibility level 130 or higher. If your user databases aren''t at that compat level yet, install sp_BlitzCache in master instead.', 16, 1);
+    RETURN;
+END;
+
 IF(@OutputType = 'NONE' AND (@OutputTableName IS NULL OR @OutputSchemaName IS NULL OR @OutputDatabaseName IS NULL))
 BEGIN
     RAISERROR('This procedure should be called with a value for all @Output* parameters, as @OutputType is set to NONE',12,1);

sp_BlitzIndex.sql

@@ -98,7 +98,7 @@ versions for free, watch training videos on how it works, get more info on
 the findings, contribute your own code, and more.
 
 Known limitations of this version:
- - Only Microsoft-supported versions of SQL Server. Sorry, 2005 and 2000.
+ - Only Microsoft-supported versions of SQL Server. Sorry, 2014 and older.
  - Index create statements are just to give you a rough idea of the syntax. It includes filters and fillfactor.
  --        Example 1: index creates use ONLINE=? instead of ONLINE=ON / ONLINE=OFF. This is because it is important 
            for the user to understand if it is going to be offline and not just run a script.

sp_BlitzWho.sql

@@ -17,12 +17,14 @@ SELECT
      WHEN CONVERT(NVARCHAR(128), SERVERPROPERTY ('PRODUCTVERSION')) LIKE '10%' THEN 0
      WHEN CONVERT(NVARCHAR(128), SERVERPROPERTY ('PRODUCTVERSION')) LIKE '11%' THEN 0
      WHEN CONVERT(NVARCHAR(128), SERVERPROPERTY ('PRODUCTVERSION')) LIKE '12%' THEN 0
+     WHEN CONVERT(NVARCHAR(128), SERVERPROPERTY ('PRODUCTVERSION')) LIKE '13%'
+          AND CAST(PARSENAME(CONVERT(NVARCHAR(128), SERVERPROPERTY ('PRODUCTVERSION')), 2) AS INT) < 5026 THEN 0
 	 ELSE 1
   END
 ) = 0
 BEGIN
 	DECLARE @msg VARCHAR(8000);
-	SELECT @msg = 'Sorry, sp_BlitzWho doesn''t work on versions of SQL prior to 2016.' + REPLICATE(CHAR(13), 7933);
+	SELECT @msg = 'Sorry, sp_BlitzWho doesn''t work on versions of SQL prior to 2016 SP2.' + REPLICATE(CHAR(13), 7933);
 	PRINT @msg;
 	RETURN;
 END;

sp_kill.sql

@@ -651,10 +651,10 @@ For more info, visit http://FirstResponderKit.org
 		SET @ObjectFullName = @OutputDatabaseName + N'.' + @OutputSchemaName + N'.' + @OutputTableName;
 
 		/* Create table if it doesn't exist */
-		SET @StringToExecute = N'USE ' + @OutputDatabaseName + N';
+		SET @StringToExecute = N'
 			IF EXISTS(SELECT * FROM ' + @OutputDatabaseName + N'.INFORMATION_SCHEMA.SCHEMATA WHERE QUOTENAME(SCHEMA_NAME) = ''' + @OutputSchemaName + N''')
 			AND NOT EXISTS (SELECT * FROM ' + @OutputDatabaseName + N'.INFORMATION_SCHEMA.TABLES WHERE QUOTENAME(TABLE_SCHEMA) = ''' + @OutputSchemaName + N''' AND QUOTENAME(TABLE_NAME) = ''' + @OutputTableName + N''')
-			CREATE TABLE ' + @OutputSchemaName + N'.' + @OutputTableName + N' (
+			CREATE TABLE ' + @ObjectFullName + N' (
 				Id INT IDENTITY(1,1) NOT NULL PRIMARY KEY CLUSTERED,
 				ServerName NVARCHAR(128) NULL,
 				CheckDate DATETIMEOFFSET NULL,