[zts212653]

What

• Centralize directory-entry durability in one syncDirectory helper.
• Skip only directory-handle fsync on win32, where Node returns EPERM.
• Route all six Collective persistence paths through that helper: bootstrap credentials, Service state, GitHub App setup, Connector state, attachment custody, and context-reference keys.
• Add a regression that reproduces the Windows EPERM after the bootstrap file itself was durably written, plus a counterexample proving non-Windows I/O errors still propagate.

Why

The real Windows desktop consumer failed first activation of official.collective-connector at dist/business/service/bootstrap-files.js:69, the directory handle's sync() call. The file write and file-handle sync() had already completed. Catching EPERM broadly would hide real permission or storage failures, so the fix uses the explicit platform contract instead.

Test evidence

• Regression before implementation: Windows case failed with injected EPERM; non-Windows EIO case already propagated.
• pnpm --dir packages/collective-connector build — pass.
• pnpm --dir packages/collective-connector typecheck — pass.
• pnpm --dir packages/collective-connector test — pass: lifecycle 13, control 62, transport 3, business 438.
• pnpm --dir packages/collective-connector test:installed — pass: packaged lifecycle/CLI 5.
• pnpm --dir packages/collective-connector test:source — pass: source/package continuity 4.
• git diff --check — pass.

Boundaries

• File-handle sync(), atomic rename/link behavior, privacy checks, and non-Windows directory-sync failures remain enforced.
• This PR does not change a package version, candidate/live catalog, npm publication, installation, or runtime data.
• A real Windows positive needs a subsequently published package containing this commit; that distribution acceptance is separate from source review.
• Draft PR fix(collective): recover expired first-owner setup from the owner launcher #153 overlaps bootstrap-files.ts and Service persistence and will need to rebase onto the landed helper; this PR does not change its owner-bootstrap recovery behavior.

[小太阳·砚砚/gpt-5.6-sol🐾]

[zts212653]

Superseded by #167, which landed as d051c45. Its approved exact tree contains the original Windows durability commit 7a4f778 with all eight reviewed source files byte-identical. Exact-head CI 40951084156 passed, and @clowder-ai/collective-connector@0.1.0-alpha.22 is now published with the candidate SHA1 e5bd4cd216a4416658d432b90c0cbcf46b12730a and matching SRI. Closing this source-only PR avoids a duplicate delivery path; native Windows first-activation acceptance remains a separate downstream check and is not claimed here.

[小太阳·砚砚/gpt-5.6-sol🐾]