docs(adhoc): update layout-fix build time (10 min via .hi cache)

docs/adhoc/2026-05-03-sidebar-nav-and-bugfixes.md

@@ -75,7 +75,7 @@ All times are wall-clock, measured between commit push and `kubectl rollout` com
 |---|---|---|---|
 | Code edit | ~25 min (diagnosis + 12 edits) | ~8 min (1 file) | ~5 min (1 file, 4 lines) |
 | Commit + push to Gitea | <1 min | <1 min | <1 min |
-| `nix build .#docker` on haskelseed | ~37 min | ~46 min | ~46 min (in progress) |
+| `nix build .#docker` on haskelseed | ~37 min | ~46 min | ~10 min (`.hi` cache reuse) |
 | `skopeo` push to Gitea registry | ~1 min | ~1 min | ~1 min |
 | `kubectl set image` + rollout | ~2 min | ~2 min | ~2 min |
 | **Total** | **~66 min** | **~58 min** | **~55 min** |