feat: seed public x-trends machine source for X trends discovery

[rebelchris]

What

Seeds a public x-trends ("Trending on X") machine source — migration + seeds/Source.json — as the attribution target for tweets injected by yggdrasil's X personalized-trends discovery engine (dailydotdev/yggdrasil#695).

Why public

Posts inherit the source's private flag at ingestion, and private posts don't qualify for trend collections — which is the entire purpose of the injected tweets (unknown was considered and rejected for exactly that reason: it's a private source). The tweets stay off feeds regardless through the opt-in social:twitter content type, so public here doesn't surface anything to users who haven't opted into social content.

Notes

• Deploy ordering: this must be live before the yggdrasil twitter:trends source is activated — the twitter processor drops posts whose explicit source_id has no source row.
• Interim logo reuses the collections logo, same as the trends source did in feat: add trends machine source #3924.
• Idempotent (ON CONFLICT DO NOTHING); verified against a local DB where the row already existed.

🤖 Generated with Claude Code

[pulumi]

🍹 The Update (preview) for dailydotdev/api/prod (at d373f99) was successful.

Resource Changes

    Name                                                       Type                                  Operation
~   vpc-native-update-current-streak-cron                      kubernetes:batch/v1:CronJob           update
~   vpc-native-post-analytics-history-day-clickhouse-cron      kubernetes:batch/v1:CronJob           update
+   api-sub-api.contribution-action-completed-founding         gcp:pubsub/subscription:Subscription  create
-   vpc-native-api-db-migration-46e10cfe                       kubernetes:batch/v1:Job               delete
+   vpc-native-api-clickhouse-migration-58fa020e               kubernetes:batch/v1:Job               create
~   vpc-native-post-analytics-achievements-cron                kubernetes:batch/v1:CronJob           update
~   vpc-native-expire-super-agent-trial-cron                   kubernetes:batch/v1:CronJob           update
-   vpc-native-api-clickhouse-migration-46e10cfe               kubernetes:batch/v1:Job               delete
+   vpc-native-api-db-migration-58fa020e                       kubernetes:batch/v1:Job               create
~   vpc-native-clean-channel-highlights-cron                   kubernetes:batch/v1:CronJob           update
~   vpc-native-clean-zombie-user-companies-cron                kubernetes:batch/v1:CronJob           update
~   vpc-native-generic-referral-reminder-cron                  kubernetes:batch/v1:CronJob           update
~   vpc-native-deployment                                      kubernetes:apps/v1:Deployment         update
~   vpc-native-update-views-cron                               kubernetes:batch/v1:CronJob           update
~   vpc-native-clean-old-notifications-cron                    kubernetes:batch/v1:CronJob           update
~   vpc-native-user-profile-analytics-history-clickhouse-cron  kubernetes:batch/v1:CronJob           update
~   vpc-native-personalized-digest-cron                        kubernetes:batch/v1:CronJob           update
~   vpc-native-update-trending-cron                            kubernetes:batch/v1:CronJob           update
~   vpc-native-channel-highlights-cron                         kubernetes:batch/v1:CronJob           update
~   vpc-native-sync-subscription-with-cio-cron                 kubernetes:batch/v1:CronJob           update
~   vpc-native-update-tag-materialized-views-cron              kubernetes:batch/v1:CronJob           update
~   vpc-native-subscription-anniversary-achievements-cron      kubernetes:batch/v1:CronJob           update
~   vpc-native-squad-posts-analytics-refresh-cron              kubernetes:batch/v1:CronJob           update
~   vpc-native-post-analytics-clickhouse-cron                  kubernetes:batch/v1:CronJob           update
~   vpc-native-clean-zombie-users-cron                         kubernetes:batch/v1:CronJob           update
~   vpc-native-temporal-deployment                             kubernetes:apps/v1:Deployment         update
~   vpc-native-personalized-digest-deployment                  kubernetes:apps/v1:Deployment         update
~   vpc-native-rotate-weekly-quests-cron                       kubernetes:batch/v1:CronJob           update
~   vpc-native-validate-active-users-cron                      kubernetes:batch/v1:CronJob           update
~   vpc-native-update-highlighted-views-cron                   kubernetes:batch/v1:CronJob           update
~   vpc-native-materialize-yearly-best-post-archives-cron      kubernetes:batch/v1:CronJob           update
~   vpc-native-rotate-daily-quests-cron                        kubernetes:batch/v1:CronJob           update
~   vpc-native-user-profile-analytics-clickhouse-cron          kubernetes:batch/v1:CronJob           update
~   vpc-native-clean-zombie-images-cron                        kubernetes:batch/v1:CronJob           update
~   vpc-native-generate-search-invites-cron                    kubernetes:batch/v1:CronJob           update
~   vpc-native-clean-stale-user-transactions-cron              kubernetes:batch/v1:CronJob           update
~   vpc-native-update-source-public-threshold-cron             kubernetes:batch/v1:CronJob           update
~   vpc-native-ws-deployment                                   kubernetes:apps/v1:Deployment         update
~   vpc-native-materialize-monthly-best-post-archives-cron     kubernetes:batch/v1:CronJob           update
~   vpc-native-check-analytics-report-cron                     kubernetes:batch/v1:CronJob           update
~   vpc-native-bg-deployment                                   kubernetes:apps/v1:Deployment         update
... and 16 other changes