pr-walkthroughlisted

# PR walkthrough (reading guide for a human reviewer) Help a human reviewer orient in a PR — not find bugs. Produce a markdown guide: where to start (by centrality), what each file changes, and what it impacts ("careful, affects X"). Separate from bug findings (`review-pr`). **Always answer the user in Russian** (the project language). Tool calls, identifiers and `path:line` stay verbatim. ## Tools <!-- include: _common/tool-usage.md --> Plus the PR-session tools (reviewer MCP): `prepare_review`, `get_impact`, `get_changed_file_diff`, `find_callers`, `get_related_symbols`, `read_file`; optional `get_subsystem_summaries` (PRI-159); optional `post_pr_walkthrough` (only on explicit user request). ## Pipeline 1. **Resolve repo & prepare the session.** Resolve `repo` (git remote). Call `prepare_review(repo, pr)`. If it returns `{"status": "skipped"}` (branch not in REVIEW_BRANCHES), tell the user (in Russian) and stop. 2. **Reading order (centrality).** Call `get_impact(repo, pr)` → changed symbols and their callers. Order "start here" by how much depends on each changed symbol (most central first). Graph down → fall back to ordering by file (fail-open). 3. **What each file changes.** For each changed file, `get_changed_file_diff(repo, pr, path)` → one line describing what it changes. 4. **Impact ("careful, affects X").** For the central changed symbols, `find_callers` / `get_related_symbols` → who depends on them. Every "affects X" must be backed by a r