Two PR-review fixes on 9459:
1. WalkerDispatcher.Delete used to panic on a (nil, nil) RPC return —
add a defensive nil-response check so the walk halts cleanly
instead. Spotted by coderabbit.
2. The retentionWindow=maxTTL comment in runShard claimed PromotedHash
"stays empty" in fallback mode, which gemini correctly pointed out
is only true once rules are active. During bootstrap (rules
compiled but IsActive=false) MaxEffectiveTTL is 0 while
PromotedHash counts every non-disabled rule, so promoted becomes
non-empty and the next post-activation run hits the recovery
branch. That's the intended bootstrap walk — rewrite the comment
to explain it rather than misstate the invariant.
Test: pins nil-response → error path on WalkerDispatcher.
Chris Lu
e396e20faa