LITE: the surfaces that show the newest snapshot say when it was collected (part of #4966)

[erikdarlingdata]

Part of #4966.

What changes

Lite's tabs that show the newest snapshot now say when it was collected. A reader can tell a stale snapshot from a fresh one. The time is in the display zone, to the second, worded the way the Automatic Tuning grid words its Collected column.

• Grids get a Collected column. It comes last and sorts by the stored time. The grids are CPU Scheduler, the Latch and Spinlock grids on Latches & Spinlocks, the five Configuration grids (Server, Database, Database Scoped, Query Store Health, Trace Flags) and Running Jobs. The text is worded per row, so a grid whose rows come from different snapshots shows each row's own time.
• Summary strips end with Collected and the time. The strips are the Memory Overview strip, the Plan Cache strip and the Session Stats strip. With no snapshot the strip shows its own empty marker (--, and N/A on Session Stats) and no time.
• The Session Stats read also returns the newest collection's own time in the last bucket. The strip's Top Application and Top Host come from that collection. The trend point's time is the bucket start (or the bucket's first collection), so it would show the wrong time. This is the only read that changed. The CPU Scheduler, Memory and Plan Cache reads already returned the snapshot's time, and the latch, spinlock, configuration and running-jobs rows already carried it.
• New row members. The latch, spinlock and running-jobs rows get CollectionTimeLocal. The five configuration rows get CaptureTimeLocal, because their stored time is capture_time. A new CpuSchedulerGridRow carries the snapshot's time beside each metric row.

Later fixes

• The Darling viewer's five Configuration grids (Server, Database, Database Scoped, Query Store Health, Trace Flags) now end with the same Collected column as Lite, worded in the display zone to the second and sorted by the stored capture time. This also turns the red Query Store pin green, and the pin now expects the new last column.
• The Lite strip-time helper is reshaped so the T-SQL member scan reads it whole (no new known-truncated entry).
• The Lite Query Store Health Collected doc now says the data is captured hourly, not on connect.
• The viewer's grid-time sort census now lists the five new Collected columns, so each is checked to sort by its stored time, not its text.

Test plan

• Grid columns. Nine rows are added to the existing grid-time table in GridTimeColumnSortMemberTests. Each new column must exist, bind the text member and sort by a stored DateTime on its row type. RED with the nine XAML columns taken out: 9 table cases fail, plus TheScan_ReadsEveryPinnedColumnAsATime (10 in all).

• Strips. ASummaryStrip_EndsWithItsSnapshotsCollectedTime (3 cases) checks that each strip ends with a Collected label and a named value. Four code pins check that the code fills each surface from the snapshot's own time. RED with the three strip text blocks taken out: 3 of 3 fail.

• Text. The new SnapshotCollectedTimeTests check three things for all nine row types. The text is the stored time in the display zone to the second, in Server and UTC modes. The second pass of the autumn repeated hour keeps its -05:00 suffix. Two rows with different times each show their own.

• Strip and CPU Scheduler rows. The strip text is the time in the given zone, and the empty marker with no snapshot. The CPU Scheduler rows each carry the snapshot's time, and there are no rows (so no time) without a snapshot.

• Read. A live DuckDB test in LiteCpuSessionsPlanCacheTrendBucketingTests: a bucket holding two collections returns the newer collection's time, not the bucket start.

• Totals. 550 passed, 0 failed, 0 warnings. Classes run: SnapshotCollectedTimeTests, GridTimeColumnSortMemberTests, LiteCpuSessionsPlanCacheTrendBucket*, HistoryGridZoneTests, DisplayZoneTextFrameTests, RepoFileAdoption*, DocCommentHygiene*, CommentFilterAdoption*, and every class whose name has CpuScheduler, SessionStats, PlanCache, ServerTab, AzureSqlDatabase, ServerTimeHelper, Config or StoredServerClock.

• Not run against the old code. The text, strip-text, CPU Scheduler row and live Session Stats tests call members that do not exist before this change. They cannot compile there, so their RED is "does not compile" and I did not run them red.

• Not run: the full suite. No app was started, so nobody has looked at the new columns or strips on screen.

• Later fixes: built Darling.Tests and Lite.Tests on macOS, 0 errors. Not run here: Darling.Tests cannot start on macOS (needs the WindowsDesktop runtime) and Lite.Tests never runs on this Mac. The new ViewerConfigGridCollectedColumnTests (5 grid pins, 1 row-text test), the updated Query Store pin and the member-scan test are proven by CI only; their REDs (viewer without the column, helper with the property pattern) are CI-only too.

Notes

• The CPU Scheduler grid is a metric and value list with column sorting switched off on purpose, because its row order is the point. Every row shows the same time. The new column still names its stored time as its sort member, which the grid-time table requires. Header clicks stay off there.
• The Plan Cache strip puts Collected after the recommendation hint, as the last item. In a narrow window the strip can clip at the right edge. I did not change its layout.
• The shared CPU Scheduler snapshot interface leaves the time out on purpose, because each app words its own time. The shared code is untouched, and Lite wraps the shared metric rows instead. The Darling viewer half is on its own branch.
• A Trace Flags capture with every flag off stores no rows. That grid is empty and shows no time.

CHANGELOG

No entry in this PR. The release owner adds it under [Unreleased].

SECTION: Added
ENTRY:
- **Lite's tabs that show the newest snapshot now say when it was collected** ([#5032]) - The CPU Scheduler, Latches & Spinlocks, Configuration and Running Jobs grids have a Collected column in Lite, and the Darling viewer's five Configuration grids have the same column, and the Memory, Plan Cache and Session Stats summary strips end with Collected and the time, in the display zone to the second, so a stale snapshot no longer looks like a fresh one. The Session Stats time is the newest collection in the last bucket, which is where its Top Application and Top Host come from.
REF:
[#5032]: https://github.com/erikdarlingdata/PerformanceMonitor/pull/5032