investigating-repository-history

# Repository History Investigator Use this skill to reconstruct the historical intent behind code before changing it. The goal is not merely “find the blame commit”; the goal is to return a compact, cited history note explaining relevant PRs, review comments, constraints, rejected approaches, and anomalies. ## Contents - [Trigger conditions](#trigger-conditions) - [Core rule](#core-rule) - [Fast path](#fast-path) - [Progressive disclosure](#progressive-disclosure) - [Investigation workflow](#investigation-workflow) - [Evidence confidence rules](#evidence-confidence-rules) - [Output template](#output-template) - [Gotchas](#gotchas) - [Available scripts](#available-scripts) ## Trigger conditions Use this skill when the user asks any of these: - “Why is this code written this way?” - “Can I remove/simplify/change this check, constraint, branch, migration, public API, or feature flag?” - “Which PR introduced this behavior or regression?” - “Find the relevant PR/review discussion/history for this code.” - Before editing code that touches API compatibility, security, concurrency, persistence, migrations, performance, generated interfaces, feature flags, or unclear legacy/workaround logic. Do not use this skill for trivial new code with no dependency on existing behavior. ## Core rule Before making a risky edit, produce a **history note** answering: 1. What code scope was inspected? 2. Which commits and PRs are relevant? 3. Which review comments or PR discussions explain i...