Motivation

• Pin maturin in CI to ensure reproducible wheel builds across platforms.
• Add a scheduled canary workflow to exercise the latest allowed maturin to detect upstream regressions early.
• Bump the crate and packaging version and correct blocker semantics so ancestor blocker checks use the starting row's target as the anchor.

Description

• Updated multiple GitHub Actions workflows to pass maturin-version: "1.12.5" to PyO3/maturin-action@v1 (.github/workflows/CI.yml, .github/workflows/build-wheels.yml).
• Added a new scheduled maturin-canary.yml workflow that builds wheels on a small matrix to test the latest allowed maturin.
• Bumped Rust crate version from 0.1.3 to 0.1.4 in Cargo.toml and updated Cargo.lock, and bumped the conda recipe recipe/meta.yaml version to 0.1.4 and build number to 1.
• Changed blocker semantics in propagate_target_rows in src/lib.rs to use an anchor_target (the start row's target) for blocker checks across ancestor traversal and removed the initial self-node blocker pre-check, updated the doc comment, and adjusted tests accordingly including adding blocker_checks_use_start_target_as_anchor_across_ancestors and updating the self-blocker test expectation.

Testing

• Ran cargo test (Rust unit tests) and the test suite completed successfully.

Codex Task