#4396 On Windows, findAllGlobalSince and findHistoryByDefinition stat the output summary index where the by-name skip expects no I/O

On Windows, two tests in src/infrastructure/persistence/yaml_output_repository_test.ts have failed on 27 of the 29 Windows Compatibility runs since 2026-10-31 00:15Z (latest https://github.com/swamp-club/swamp/actions/runs/41864132261, dd6591148):

• findAllGlobalSince: skips a file named before the cutoff without a stat or read, however fresh its mtime (line 2344)
• findHistoryByDefinition: with since, skips a file named before it without a stat or read, and keeps one started exactly at it (line 2586)

The stat/read spy is expected to record nothing but records two hits:

[
  "C:\Users\[REDACTED]\AppData\Local\Temp\swamp-test-…\.swamp\_output_summaries\v1\<hash>\command\shell",
  "C:\Users\[REDACTED]\AppData\Local\Temp\swamp-test-…\.swamp\_output_summaries\v1\<hash>\command\shell",
]

Both paths are under the output summary index directory. The tests were green on Windows until 24be9a5b9 (swamp-club#4145), which made history reads answer from the checkout-local summary index. On Windows that index is stat'ed or read where the test expects the by-name skip to avoid any I/O. Either the summary-index read path does I/O on Windows only, for example because a path or key built with / misses a native \ path, or the spy must allow the index directory.