Stop SubscriptionHydrator from skipping exclusive originals on retweets

[Pitchfork-and-Torch]

Bug

SubscriptionHydrator fetches TES exclusive-conversation authors by candidate.tweet_id (the wrapper). IneligibleSubscriptionFilter keeps subscription_author_id = None.

TES stores exclusive_conversation_author_id on the original Super Follow post. An in-network retweet of that original is a new tweet id. The hydrator looks up the wrapper, TES returns none / miss, Hydrator::update_all skips the write, and the filter treats None as eligible.

Phoenix already drops OON retweets. In-network retweets of exclusive originals survive to this filter. LanguageCodeHydrator, MediaInfoHydrator, EngagementCountsHydrator, and ads brand-safety already key TES / media by get_original_tweet_id(). This hydrator does not.

VF DropExclusiveTweetContentRule is a later post-select gate. It is not this class. This is the mixer Super Follow filter looking up the wrong tweet. Not #119 (VF primary wrapper id). Not #118 (QuoteHydrator quoted id on retweets). Not #116 (OON retweet original Recs).

• Entry: SubscriptionHydrator::hydrate_from_client / cache_key
• Sink: IneligibleSubscriptionFilter (None => keep)
• Break: TES exclusive author lives on the original tweet; hydrator and cache key the wrapper
• Viewer effect: a non-subscriber who follows the retweeter gets Super Follow exclusive content in For You
• Twin: LanguageCodeHydrator cache_key / TES lookup via get_original_tweet_id()

Fix

Key TES and the hydrator cache by get_original_tweet_id(). Native exclusive posts are unchanged (wrapper id == original id). Public posts still hydrate as None and stay eligible.

Quote-of-exclusive is leftover. get_original_tweet_id() does not walk quoted_tweet_id. Separate class.

Tests

• Native exclusive post still reads TES at the wrapper id
• In-network retweet of an exclusive original fills subscription_author_id from the original
• Public post stays None
• Non-subscriber loses the retweet; subscriber keeps it

cargo test cannot run. Public dump has no Home Mixer manifest. Verification of the change is on you.