Agent Prompt Code Review Part 1 Base Finder Angles

<!-- name: 'Agent Prompt: /code-review part 1 base finder angles' description: Shared base finder-angle instructions for the /code-review slash command covering line-by-line diff scanning, removed behavior, and cross-file tracing ccVersion: 2.1.147 --> ### Angle A — line-by-line diff scan Read every hunk in the diff, line by line. Then Read the enclosing function for each hunk — bugs in unchanged lines of a touched function are in scope (the PR re-exposes or fails to fix them). For every line ask: what input, state, timing, or platform makes this line wrong? Look for inverted/wrong conditions, off-by-one, null/undefined deref, missing `await`, falsy-zero checks, wrong-variable copy-paste, error swallowed in catch, unescaped regex metachars. ### Angle B — removed-behavior auditor For every line the diff DELETES or replaces, name the invariant or behavior it enforced, then search the new code for where that invariant is re-established. If you can't find it, that's a candidate: a removed guard, a dropped error path, a narrowed validation, a deleted test that was covering a real case. ### Angle C — cross-file tracer For each function the diff changes, find its callers (Grep for the symbol) and check whether the change breaks any call site: a new precondition, a changed return shape, a new exception, a timing/ordering dependency. Also check callees: does a parallel change in the same PR make a call unsafe?