Function build_dependency_bundle 

pub fn build_dependency_bundle(
    root: &Path,
    depends_on: &[String],
    config: &Config,
) -> String

Build a dependency context bundle for a worker prompt.

Returns a Markdown string to prepend to the worker prompt when the ticket has depends_on set. Returns an empty string when depends_on is empty.

Direct dependencies include: ticket id + title, full Approach section, and a capped commit-subject list. If a dependency is not yet in a terminal state, a warning is appended.

Transitive dependencies (deps-of-deps, one level deep) include only title + one-line Problem summary.