Merged, with one column-reconciliation gap closed.
The fail-closed reasoning is right and the comments carry it well: a stored snapshot whose cues were replaced by `[redacted-video-transcript]` must not be rehydrated as continuation history, because forwarding placeholder text upstream as if it were the client's real turn is worse than making the client resend. Treating it exactly like `previous_response_not_found` means no new client-visible behaviour to document. Migration 173 does not collide — the tip runs to 172.
**What I added:** `video_content_removed` to `ensureCallLogsColumns` in `src/lib/db/schemaColumns.ts`, plus a case in `tests/unit/db-schema-columns-split.test.ts`.
`resolvePreviousResponseState` now SELECTs that column on every `previous_response_id` lookup. Migration 173 creates it, but this repo carries a separate reconciliation path for lineages that skipped a migration — and on such a database the SELECT would throw `no such column: video_content_removed` instead of failing closed. That is the same hole #12470 closed for `provider_connections.last_ping_at` earlier today, so the pattern was fresh. Verified red-then-green: stubbing the new reconciliation out drops the suite to 8/9; restored, 9/9.
Validated on `release/v3.8.51`: `responses-continuation-store`, `save-call-log-persistence`, `video-bridge-log-redaction` and `db-schema-columns-split` all green (54 focused tests, 0 failures). `typecheck:core` and `lint` clean. The integration run logs `[DB] Added call_logs.video_content_removed column`, which is the reconciliation firing on a fresh test database.
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