v0.19.1

v0.19.1 (2026-05-03)

Bug Fixes

• core: Replace fcntl with portalocker for cross-platform locking (1a02be3)

The fcntl module is POSIX-only, which made import jup.core.lock fail at module load on Windows, blocking every jup command on that platform.

Replace it with portalocker, which exposes the same advisory-locking semantics (LOCK_EX, LOCK_SH, LOCK_UN) on top of fcntl on POSIX and msvcrt on Windows.

• Add portalocker>=2.10.0 as a runtime dependency
• Existing concurrency tests (tests/concurrency/test_locking.py) pass
  unchanged on Windows
• Catch portalocker.exceptions.LockException alongside OSError so the
  existing RuntimeError contract is preserved

Scope is intentionally narrow: this fix unblocks startup. Other Windows compat issues observed during testing (symlink creation requires Developer Mode/admin; some integration tests assume POSIX paths) remain to be addressed in follow-up work.

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Detailed Changes: v0.19.0...v0.19.1