Fix EPERM on WSL2 9P + EFS by replacing fs.copyFileSync with read+write shim

[WeathermanTony]

Summary

openwolf init and openwolf update fail with EPERM when run from WSL2 on a Windows path that's EFS-encrypted. Root cause is not OpenWolf — it's a libuv quirk: fs.copyFileSync uses the copy_file_range syscall on Linux as a fast path, and that syscall fails on the WSL2 9P filesystem when the destination directory has the NTFS Encrypted attribute. Plain read()+write() works fine in the same conditions.

This PR adds a safeCopyFile shim in utils/fs-safe.ts (matching the existing writeJSON/writeText safe-write pattern) and routes all 12 fs.copyFileSync call sites in cli/init.ts and cli/update.ts through it.

Reproduction

# Windows side
mkdir J:\test-efs
cipher /e J:\test-efs

# WSL2 side
cd /mnt/j/test-efs
openwolf init
# -> Error: EPERM: operation not permitted, copyfile '.../OPENWOLF.md'

After this PR: init and update succeed; new files correctly inherit the parent's Encrypted attribute via standard NTFS inheritance.

Why a shim instead of switching to streams or cp

• Matches the existing fs-safe.ts style (already wraps writeFileSync for the Windows-rename quirk)
• Synchronous, drop-in for fs.copyFileSync — every call site is a one-token rename
• Preserves file mode (best-effort) for the hook scripts
• read+write is fine for the file sizes OpenWolf copies (small templates and hook scripts; not multi-GB blobs where copy_file_range would actually matter)

Verified isolation of the bug

WSL `echo > new_file.txt` to encrypted dir   → OK, file inherits Encrypted=True
WSL `echo > existing.txt`  to encrypted file → OK, overwrite works
WSL `cp src dest` (overwrite)                → OK, plain read+write
Node `fs.copyFileSync(src, new_dest)`        → FAIL EPERM
Node `fs.copyFileSync(src, existing)`        → FAIL EPERM
Node `fs.writeFileSync(d, fs.readFileSync(s))` → OK (this is the shim)

Test plan

• Reproduce the original failure on a fresh EFS-encrypted directory under /mnt/j/...
• Apply the patch, confirm openwolf init runs to completion (13 template files copied, hooks registered, daemon started)
• Verify newly-written files inherit the parent's Encrypted attribute
• pnpm exec tsc builds clean with no new diagnostics
• Reviewer: please run on a non-WSL/non-EFS environment to confirm no regression — the shim is functionally equivalent to copyFileSync for the contents OpenWolf copies (small text/JS files), so this should be a no-op on any platform

🤖 Generated with Claude Code