Video/general search is login-walled for anonymous sessions, but the Users
tab (/api/search/user) returns public account records without a redirect, so
this exposes the one reliably-unblocked search path. A keyword yields
TikTokProfileItems (name, followers, bio, verification), deduped per query,
capped, and degraded to an ErrorItem when a query is empty/withheld.
Reuses the browser capture (generalized over XHR markers + extractor) and the
shared profile item shape. Billed per account on a new TIKTOK_USER meter
(TIKTOK_MICROS_PER_USER), surfaced on the chat subagent alongside tiktok.scrape.
Profile and search feeds are trust-gated: an anonymous headless session
gets an empty item_list (profile) or no results XHR (search), while
hashtag feeds load. A zero-item listing now yields one honest ErrorItem
(errorCode="no_items") instead of vanishing silently, and ErrorItems are
excluded from billing so a blocked target is surfaced but never charged.
