Conversation view coverage: remaining chat artifacts (test data needed)

We recently added LAVA threaded conversation views across the chat artifacts (see #1645, #1647, #1648). Every direction column we shipped was verified against real test data before merging. A wrong `directionSentValue` doesn't crash anything, it silently flips who said what, and that is not acceptable for a forensic tool. So the artifacts below are on hold until we can verify them the same way.

Here is what is left and what each one needs:

- [ ] **Vipps** (`vipps.py`) - The direction value comes straight from the app's JSON and we don't know its vocabulary (could be `INCOMING`/`OUTGOING`, `IN`/`OUT`, something else). Needs a Vipps extraction where the examiner knows which messages were sent and which were received.
- [ ] **Pinger Text Free** (`pingertextfree.py`) - Same situation. `ZDIRECTION` is emitted raw from the database and the value set is unverified. Needs a Text Free extraction with known sent/received messages.
- [x] **IMO HD** (`imoHD_Chat.py`) - Direction is already verified (`Message Status` = Sent/Received), but there is no thread column on sent rows. The fix is plumbing the `buid` through the query as a Chat Partner column. This one is a dev task, test data exists.
- [ ] **BeReal** (`BeReal.py`) - Textbook fit for the view (Thread ID, Direction, Sender all present). On hold only to avoid conflicting with the open BeReal rework in #1637. Once that lands, the view is a metadata-only addition.

**How to help:** if you have (or can generate) a test extraction for any of these apps where you know the ground truth of who sent what, drop a note here. The validation itself is quick: we run the artifact against your data and confirm the sent/received split matches what you know to be true. That's it.

If you want to see the pattern these conversions follow, #1647 and #1648 are good examples, including how we derive direction from account owner data already inside the evidence.