Stop VF hydrator from overwriting in-network verdicts with OON

[Pitchfork-and-Torch]

Bug

VFCandidateHydrator fetches in-network primaries as TimelineHome and ancestors/quotes as TimelineHomeRecommendations, then merges with all_results.extend(oon_result) so the later key wins.

Thunder sets ancestors = [in_reply_to, conversation_root] on in-network replies. When a parent and reply land in the same batch, the parent tweet_id is in both maps. The selected in-network tweet then gets the Recommendations verdict.

TimelineHome is base_home_rules() only. Recommendations adds OON-only Drop rules (NSFW_HIGH_PRECISION_DROP, DO_NOT_AMPLIFY_DROP, MALICIOUS_URL_DROP, SPAM_HIGH_RECALL_DROP, NSFW author drops that are Interstitial in-network / Drop OON). VFFilter hard-drops Action::Drop.

This is a successful VF result applied at the wrong safety level. Not fail-open on miss, and not missing labels.

Fix

Keep both maps. Look up candidate.tweet_id only from the map that matches candidate.in_network. Ancestor/quote ancillary checks still use Recommendations. retweeted_tweet_id stays on TimelineHome.

Tests

• In-network parent that is also a sibling reply ancestor keeps the TimelineHome interstitial and is not overwritten by a Recommendations Drop.
• True OON primary still uses Recommendations.