Comment/XML-doc changes only:
- add summaries to ~10k test methods, fixtures, fakes and helpers
(+ <param> on theories, <returns> on async Task methods,
<inheritdoc/> on interface implementations the checker can resolve)
- strip ~2.6k project-tracking references (WP*, P*-*, row-NN, Task N,
#NN, Component-0NN) from comments, keeping the explanatory text;
reword false positives in comments only
- real docs on fakes implementing BCL/library interfaces
(IDisposable, ILogger, IOptionsMonitor, IAsyncLifetime)
- reword the last 5 src/ false positives (CWE-1236, failures-1,
year-0001, M365)
Only non-comment edits: four one-line nested classes split across lines
so members can carry docs. Build 0 errors / 0 warnings.
Retention purge deletes Forwarded/Reconciled rows older than the cutoff and
reclaims pages via incremental_vacuum; Pending rows are never purged on age
alone (would lose audit data that never reached central). Temp-table purge set
avoids the SQLite 999-param limit; runs under _writeLock. (PLAN-04 Task 1, S1/U2)