Rework CDC exclusion: program_name->job_id via msdb, text fallback (#1096)

Replace the text-only CDC filter with a precise, two-tier signal:

1. Primary: resolve capture job_id(s) from msdb.dbo.cdc_jobs (job_type =
   'capture') and match the running session by decoding its SQL Agent
   program_name ('SQLAgent - TSQL JobStep (Job 0x<job_id> : Step N)').
   The decode -- CONVERT(uniqueidentifier, CONVERT(binary(16),
   SUBSTRING(program_name, 32, 32), 2)) -- was validated by round-tripping
   real msdb.dbo.sysjobs rows. This is CDC-specific and never hides other
   Agent jobs.

2. Fallback: when the account can't read msdb.dbo.cdc_jobs (or the table
   doesn't exist -- it is created lazily on first CDC config), match the
   whole batch/object text (sp_MScdc_capture_job / sp_cdc_scan).

The msdb reference is deferred through sp_executesql inside TRY/CATCH so an
inaccessible msdb raises a *catchable* error (not an uncatchable cross-db
916) and the query degrades to the text path instead of failing. Verified
against SQL 2016: with cdc_jobs absent, the TRY/CATCH sets @cdc_readable=0,
the batch completes, and the text fallback engages.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: erikdarlingdata

Dashboard/Services/DatabaseService.NocHealth.cs

@@ -766,14 +766,44 @@ private async Task<List<LongRunningQueryInfo>> GetLongRunningQueriesAsync(
             string miscWaitsFilter = excludeMiscWaits
                 ? "AND r.wait_type NOT IN (N'XE_LIVE_TARGET_TVF')" : "";
             // CDC capture runs continuously as a SQL Agent job (EXEC sys.sp_MScdc_capture_job -> sys.sp_cdc_scan),
-            // so it permanently exceeds the duration threshold. Filter on request text, not program_name, to stay
-            // CDC-specific and avoid hiding unrelated Agent jobs (ETL, index maintenance). Keep NULL text (encrypted
-            // modules) visible -- only drop rows we can positively identify as CDC.
-            string cdcFilter = excludeCdc
-                ? "AND (t.text IS NULL OR (t.text NOT LIKE N'%sp_MScdc_capture_job%' AND t.text NOT LIKE N'%sp_cdc_scan%'))" : "";
+            // so it permanently exceeds the duration threshold and none of the wait_type filters above catch it.
+            //
+            // Primary signal: resolve the capture job_id(s) from msdb.dbo.cdc_jobs and match the running session via
+            // its SQL Agent program_name ('SQLAgent - TSQL JobStep (Job 0x<job_id> : Step N)'). This is CDC-specific
+            // and never hides unrelated Agent jobs. The msdb reference is deferred through sp_executesql inside
+            // TRY/CATCH so a login without msdb access gets a *catchable* error (not an uncatchable cross-db 916) and
+            // cleanly falls back to a text match on the whole batch/object text.
+            string cdcSetup = excludeCdc ? @"
+                DECLARE @cdc_capture_jobs TABLE (job_id uniqueidentifier PRIMARY KEY);
+                DECLARE @cdc_readable bit = 0;
+                BEGIN TRY
+                    INSERT @cdc_capture_jobs (job_id)
+                    EXEC sys.sp_executesql N'SELECT cj.job_id FROM msdb.dbo.cdc_jobs AS cj WHERE cj.job_type = N''capture'';';
+                    SET @cdc_readable = 1;
+                END TRY
+                BEGIN CATCH
+                    SET @cdc_readable = 0;
+                END CATCH;
+" : "";
+            string cdcFilter = excludeCdc ? @"
+                    AND NOT
+                    (
+                        (
+                            @cdc_readable = 1
+                            AND s.program_name LIKE N'SQLAgent - TSQL JobStep (Job 0x%'
+                            AND TRY_CONVERT(uniqueidentifier, TRY_CONVERT(binary(16), SUBSTRING(s.program_name, 32, 32), 2))
+                                IN (SELECT j.job_id FROM @cdc_capture_jobs AS j)
+                        )
+                        OR
+                        (
+                            @cdc_readable = 0
+                            AND t.text IS NOT NULL
+                            AND (t.text LIKE N'%sp_MScdc_capture_job%' OR t.text LIKE N'%sp_cdc_scan%')
+                        )
+                    )" : "";
 
             string query = @$"SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
-
+                {cdcSetup}
                 SELECT TOP(@maxResults)
                     r.session_id,
                     DB_NAME(r.database_id) AS database_name,