General branch review

bash

git diff --stat origin/main...HEAD   # scope first
git diff origin/main...HEAD

Read the changed files in full — a hunk is rarely enough to judge correctness. Look for:

Bugs — logic errors, DropWithContext values not released on every exit path (the fix is defer_drop!/DropGuard, not more drop_with calls), borrow/aliasing mistakes, unhandled error paths.
CPython divergence — different results, exception types or messages, missing attributes. Check anything you're unsure of with python-playground.
Sandbox escapes — sandboxed code reaching the host filesystem, environment, network or subprocesses.
Resource-limit escapes — allocations not charged to the tracker (an unbounded or amplifying String build without StringBuilder), unbounded loops, recursion without a depth guard.
Performance — regressions the branch introduces, and improvements you spot.
Verbose comments — docstrings and comments should be concise as per CLAUDE.md.
Cleanups — duplication, misplaced logic, functions grown too complex.
./limitations/ — a new divergence with no entry is a finding.

Report

Concise, most severe first. Per finding: file:line, what's wrong, the concrete failure it causes. Don't pad with what the branch got right.

Report only, unless the user asks for fixes.