PLAYBOOK: Run a real shadowban audit (not a vibe check)

PLAYBOOK: Run a real shadowban audit (not a vibe check)
Four tests, in order, on a logged-out browser:
— Search-suggestion test: type your @ — do you autocomplete?
— Search-ban test: search your exact recent post text — does it appear in Latest?
— Reply-deboost test: reply to a big account, then check if your reply shows logged-out or sits under 'Show more replies'
— Ghost test: have someone not following you check if your replies appear in their thread view
Confirmed mechanic: reply-deboosting and search filtering are separate systems with separate triggers. Rumored: 'shadowban' as one switch — it isn't. Knowing which test fails tells you which behavior to fix.