Meta Ads source: add video_thruplay_watched_actions to AdStats schema

Problem

The Meta Ads data warehouse connector's AdStats schema (posthog/temporal/data_imports/sources/meta_ads/schemas.py) does not request video_thruplay_watched_actions from the Meta Marketing API /insights endpoint.

This field is the standard metric for ThruPlays (15 seconds of viewing or video completion, whichever is shorter) — the primary optimization objective for video campaigns. Without it, users can only access actions.video_view which represents 3-second video views, a ~3–9× different metric.

The schema already includes the related percentile fields (video_p25_watched_actions through video_p100_watched_actions) and video_30_sec_watched_actions, so this appears to be an oversight rather than an intentional exclusion.

Proposed fix

Add "video_thruplay_watched_actions" to the field_names list for MetaAdsResource.AdStats (and ideally AdsetStats and CampaignStats as well):

"field_names": [
    # ... existing fields ...
    "video_30_sec_watched_actions",
    "video_thruplay_watched_actions",  # <-- add this
    "video_p25_watched_actions",
    # ...
]

Context

• This is the same field that the Airbyte Facebook Marketing connector re-added in v4.2.0 after a similar omission.
• The Meta Python Business SDK lists video_thruplay_watched_actions as a standard field on AdsInsights.
• Meta's API documentation confirms ThruPlay is a first-class metric available on all insight endpoints.

Impact

Any PostHog user running video ad campaigns on Meta optimizing for ThruPlays cannot get their primary KPI from the data warehouse. The only workaround is to pull the data separately via Meta's API and load it as a custom source.

Start in posthog/temporal/data_imports/sources/meta_ads/schemas.py and inspect the field_names list for MetaAdsResource.AdStats, then compare the related AdsetStats and CampaignStats schemas. Add video_thruplay_watched_actions where appropriate and verify that the Meta Ads insights request includes the field for the intended resources.