qstack-blast-radiuslisted

# QStack blast radius Find the breakage that a symbol search or diff review would miss. The result is analysis, not permission to edit, commit, push, publish, deploy, or message anyone. ## Trace the risk 1. Resolve the exact change from the user's files, diff, branch, or recent work. Read the surrounding implementation and repository instructions. 2. State the one critical fact the change is safe because of. Use a second fact only when the safety case truly has two independent hinges. 3. Follow effects beyond direct callers. Check pinned dependency source and local patches, lifecycle timing, persisted data, wire formats, other languages reading the same bytes, feature flags, generated artifacts, and downstream consumers. Cite real paths and lines. A search with no matches is evidence when its scope is stated. 4. Separate confirmed risks from cleared risks. For each confirmed risk, name the failure path, likelihood, impact, and cheapest decisive check. ## Prove the critical fact Push each safety fact as far down this ladder as is practical: 1. A claim only. 2. Direct source evidence at a real path and line. 3. A traced bad case that cannot reach the failure. 4. A script or test that executes the real shipped code and fails loudly when the fact is false. 5. A reproduction in the running artifact. Anything below level 4 remains **unproven**. Say where proof stopped. Do not round a plausible writeup up to a verified conclusion. For analysis-only wor