Implements a pull-based merge workflow by wiring the merger pull helpers from the engine, extending the git pull and stash routes, and aligning the `MergeAdvanceNotice` and `StashConflictModal` components to gate dismissal on stash drop. The `run-audit` module is updated with pull mutation documenta
Fusion-Task-Id: FN-5419
Co-authored-by: Fusion (runfusion.ai) <noreply@runfusion.ai>
Fusion-Task-Id: FN-5419
Implements stash conflict detection and resolution with a new smart pull API route, resolution endpoints, and a dedicated conflict modal UI — backed by extended git audit taxonomy and route tests.
Fusion-Task-Id: FN-5358
