Bump version to 0.1.4; use start target as anchor for blocker checks and add test

[jeromychu23]

Motivation

• Bump the crate and package metadata to 0.1.4 and keep lockfile/recipe in sync for a new bugfix release.
• Ensure blocker checks use the original start target as the anchor when traversing ancestors so propagation is not incorrectly blocked by intermediate targets.

Description

• Updated package version from 0.1.3 to 0.1.4 in Cargo.toml, Cargo.lock, and recipe/meta.yaml.
• Introduced an anchor_target (cloned from the start row's target) and passed it to has_blocker_on_node_after_target so all blocker checks across ancestor traversal use the initial anchor instead of the evolving current_target.
• Added a unit test blocker_checks_use_start_target_as_anchor_across_ancestors that constructs a multi-level scenario and asserts correct timestamp propagation when blockers are present.

Testing

• Ran cargo test which executed the updated test suite including blocker_checks_use_start_target_as_anchor_across_ancestors and all tests passed.
• The Cargo.lock was updated to reflect the version change and tests were run against that lockfile.

---

Codex Task