Add self-filtering marker to Lite collection queries

[erikdarlingdata]

Summary

Lite's own collection queries show up in Active Queries, Top Queries, Top Procedures, and Query Store results, polluting the data with monitoring overhead.

Approach

1. Inject a recognizable dummy/marker string (e.g. a SQL comment like /* PerformanceMonitorLite */) into all collection queries that Lite executes
2. Add filters to the following display queries to exclude rows matching that marker:
   • Active Queries
   • Top Queries
   • Top Procedures
   • Query Store queries

This keeps Lite's own footprint out of the results users are analyzing.

[erikdarlingdata]

Investigation Report: Self-Filtering Marker

Collection Queries (inject marker into)

6 remote collector files in Lite/Services/RemoteCollectorService.*.cs:

Collector	Source DMV/Feature	File
Query Snapshots	dm_exec_requests + dm_exec_sql_text	RemoteCollectorService.QuerySnapshots.cs
Waiting Tasks	dm_os_waiting_tasks + dm_exec_requests	RemoteCollectorService.WaitingTasks.cs
Query Stats	dm_exec_query_stats + dm_exec_sql_text	RemoteCollectorService.QueryStats.cs
Procedure Stats	dm_exec_procedure_stats (dynamic SQL)	RemoteCollectorService.ProcedureStats.cs
Query Store	query_store_runtime_stats via sp_executesql	RemoteCollectorService.QueryStore.cs
Blocked Process Report	Extended Events session	RemoteCollectorService.BlockedProcessReport.cs

All already exclude the PerformanceMonitor database. Marker (/* PerformanceMonitorLite */) goes at the top of each SQL string constant.

Display Queries (add filter to)

14 display queries in Lite/Services/LocalDataService.*.cs read from DuckDB views. Critical ones with query_text columns that need filtering:

Method	File	Current filter
GetTopQueriesByCpuAsync	LocalDataService.QueryStats.cs	Already filters WAITFOR%
GetQueryStoreTopQueriesAsync	LocalDataService.QueryStore.cs	Already filters WAITFOR%
GetLatestQuerySnapshotsAsync	LocalDataService.Blocking.cs	Already filters WAITFOR%
GetRecentBlockedProcessReportsAsync	LocalDataService.Blocking.cs	Filter blocked_sql_text + blocking_sql_text
GetRecentDeadlocksAsync	LocalDataService.Blocking.cs	Filter victim_sql_text

Plus ~9 more trend/history queries that should also filter.

Implementation approach

1. Add /* PerformanceMonitorLite */ comment to the start of all 6 collection query strings
2. Add AND query_text NOT LIKE '%PerformanceMonitorLite%' to all display queries that expose SQL text
3. Existing WAITFOR% filter lines are the natural place to add the new filter alongside