Verify at code level that the Phase 1/2 review findings were actually closed (not just self-reported): icon cache concurrency + LRU + bounded fetch (T-606), UI-thread icon delivery (T-607), install durability with Windows FlushFileBuffers / POSIX dir sync (T-613), ZIP central-directory preflight (T-612), and catalog signature cross-impl vectors (T-614). All confirmed real. Records three residuals (R1 real power-loss validation, R2 per-file fsync cost, R3 singleflight ctx caveat). Also gitignore *.code-workspace (per review recommendation). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>