[thekevinbot]

Fixes #1213
Part of #1175

Test-only. Two Rust unit tests hard-coded Unix paths:

• extension_resolution::tests::select_loadable_rejects_an_ambiguous_package_in_sorted_order builds the expected message from the same dir.join(..).display() the error uses (/pkg/a.so on Unix, /pkg\a.so on Windows).
• internal_tests::relative_root_canonicalizes_watch_root_only uses C:\ws\canonical on Windows, /ws/canonical elsewhere.

Linux assertions are unchanged in value. No product code touched.

Red/green: the red for both tests is on the Windows job in #1178, which is not on main (run https://github.com/thekevinscott/dirsql/actions/runs/37000025579). No Windows cross-compile check was possible locally (no mingw toolchain); the Windows job in #1178 is the verification.

E2E Verification

• Ran e2e suites locally for every affected SDK
• Python SDK e2e: 38 passed, 2 xfailed, 1 XPASS(strict) -- use_case_notebook_test::it_matches_native_rows_within_the_bar passes on this machine though marked strict xfail (perf: on-file row ingestion is slower than a second interpreter's json.load + sort #1202). Unrelated to this diff (only #[cfg(test)] code changed); no receipt written yet.
• TypeScript SDK e2e: pass (18 passed)
• Rust: cargo test --lib --features cli for both tests: pass
• packages/python/e2e-attestations/<branch>.json receipt -- blocked by the XPASS above
• packages/ts/e2e-attestations/<branch>.json receipt written (just e2e-attest-ts)
• Command(s) run: just preflight, just e2e-attest-python (3x, same XPASS), just e2e-attest-ts
• Result summary: preflight fails only on the two e2e-verify pairs before receipts; TS receipt now committed.

Changelog / Migrations

• skip-changelog on the commit: test-only
• Migration not required