sprang-why

name	sprang-why
description	Understand why a file or function exists — git history, decision context, team annotations. Use when the user says "/sprang-why", "why does this exist", "who wrote this", "history of this file", or "what decisions led to this".

1. Call sprang_query with $ARGUMENTS to find the matching graph node ID (file path, function name, class name).
2. Call sprang_why with the resolved node_id to retrieve: commit history, primary authors, rationale snippets, PR references, and any team annotation content.
3. Call sprang_node with the same node_id to get enriched structural context:
   • layer (name + id) and layer_mate_count — where it fits in the architecture
   • in_degree / out_degree — how coupled it is
   • has_annotation / annotation_path — whether team knowledge exists
   • Full 1-hop neighbor list
4. If has_annotation is true, display the full annotation content prominently.
5. If decision_context.change_frequency >= 10 (commits in 90 days), flag as 🔴 frequently-churning — extra care required.
6. Cross-reference PR references from decision context.
7. Summarize: purpose, origin, ownership, layer, risk level, and specific guidance before modifying (especially if risk_score > 0.7).