Six source modules each defined an identical 8-line _sc_headers(token)
function returning {"x-api-key": token, "Content-Type": "application/json"}.
Moved it to http.scrapecreators_headers() and migrated all 33 call sites.
Affected files: reddit.py, threads.py, tiktok.py, instagram.py, pinterest.py,
youtube_yt.py. Zero per-source variation, zero behavior change.
Net: -40 lines. 1022 tests pass (15 pre-existing failures unchanged).
Live smoke test: reddit search returns 12 threads with full engagement.
Ilia Alshanetsky
9dd3f21476