test(pins): whitelist download_queue_pos on raw media rows (additive widening)

The contract pin caught the §0 item 4 column surfacing on media-list
raw sqlc rows — its job. Widened additively per doctrine: rawRowKeys +
docs/contract_pins.md changelog entry. NULL for scan rows and
never-queued episodes; nothing removed or renamed.

docs/contract_pins.md

@@ -459,3 +459,12 @@ resolved unscoped map:
 Scan-sourced rows carry the inert defaults ('scan' / NULLs / 'pending');
 raw-row consumers that filter `source='scan'` (scanner paths) are unaffected.
 Nothing removed, nothing renamed.
+
+## 2026-10-30 — download_queue_pos joins media_items (additive widening)
+
+§0 item 4 of podcast-integration.md: the download pool's monotonic
+queue ticket. `download_queue_pos BIGINT` (NULL for scan rows and
+never-queued episodes) is stamped from the `podcast_queue_seq` SEQUENCE
+at enqueue time so claim order = enqueue order (the effective listening
+order). Raw-row pins (TestContractPin_MediaListBothBranches →
+rawRowKeys) whitelist the key. Nothing removed, nothing renamed.