feat: add searchSourcePosts query for squad text search

[rebelchris]

What

New GraphQL query for text-searching posts within a single source (squad), powered by the existing Mimir integration:

searchSourcePosts(
  source: ID!
  query: String!
  first: Int
  after: String
  supportedTypes: [String!]
  version: Int = 2
): PostConnection!

How

• Permissions first: ensureSourcePermissions(ctx, source) runs before any Mimir call — private squads throw FORBIDDEN for anonymous users and non-members, same gate as sourceFeed.
• Mimir request: StringListFilter on source_id, plus explicit BoolFilters for deleted = false, visible = true, banned = false. These must be explicit because Mimir only injects its safety defaults when a request carries no filters.
• No private = false filter (unlike searchPosts): the permission check already gates access, and squad members must be able to find their private squad's posts.
• Hydration: sibling resolver to mimirSearchResolver with allowPrivatePosts: true, removeHiddenPosts: true, removeBannedPosts: false, removeNonPublicThresholdSquads: false — mirroring sourceFeed's scoped-source rationale. Results preserve Mimir's ranked order via fixedIdsFeedBuilder.
• Zod validation for source/query in src/common/schema/search.ts.

Tests

6 new tests in __tests__/search.ts (Mimir mocked via proto-typed SearchResponse instances):

• public squad returns hydrated posts in Mimir ranked order
• private squad: anonymous → FORBIDDEN, non-member → FORBIDDEN, member → succeeds
• constructed SearchRequest contains the source_id filter, omits private=false, includes the three safety filters
• pagination offset math from first/after

Full search suite: 42/42 passing. Lint and build clean.

Deploy order

Merge/deploy after the mimir index PR and before the apps PR. Related PRs linked in a comment below.

🤖 Generated with Claude Code

[pulumi]

🍹 The Update (preview) for dailydotdev/api/prod (at 739695f) was successful.

Resource Changes

    Name                                                       Type                           Operation
~   vpc-native-channel-highlights-cron                         kubernetes:batch/v1:CronJob    update
~   vpc-native-clean-zombie-images-cron                        kubernetes:batch/v1:CronJob    update
~   vpc-native-worker-job-deployment                           kubernetes:apps/v1:Deployment  update
~   vpc-native-clean-zombie-users-cron                         kubernetes:batch/v1:CronJob    update
~   vpc-native-personalized-digest-deployment                  kubernetes:apps/v1:Deployment  update
~   vpc-native-user-profile-analytics-clickhouse-cron          kubernetes:batch/v1:CronJob    update
~   vpc-native-update-highlighted-views-cron                   kubernetes:batch/v1:CronJob    update
~   vpc-native-update-tag-materialized-views-cron              kubernetes:batch/v1:CronJob    update
~   vpc-native-check-analytics-report-cron                     kubernetes:batch/v1:CronJob    update
~   vpc-native-post-lifecycle-state-clickhouse-cron            kubernetes:batch/v1:CronJob    update
~   vpc-native-squad-posts-analytics-refresh-cron              kubernetes:batch/v1:CronJob    update
+   vpc-native-api-db-migration-8e5b54a6                       kubernetes:batch/v1:Job        create
~   vpc-native-clean-channel-highlights-cron                   kubernetes:batch/v1:CronJob    update
~   vpc-native-daily-digest-cron                               kubernetes:batch/v1:CronJob    update
~   vpc-native-clean-zombie-user-companies-cron                kubernetes:batch/v1:CronJob    update
~   vpc-native-subscription-anniversary-achievements-cron      kubernetes:batch/v1:CronJob    update
~   vpc-native-post-analytics-achievements-cron                kubernetes:batch/v1:CronJob    update
~   vpc-native-generate-search-invites-cron                    kubernetes:batch/v1:CronJob    update
~   vpc-native-deployment                                      kubernetes:apps/v1:Deployment  update
~   vpc-native-calculate-top-readers-cron                      kubernetes:batch/v1:CronJob    update
~   vpc-native-generic-referral-reminder-cron                  kubernetes:batch/v1:CronJob    update
~   vpc-native-clean-expired-better-auth-sessions-cron         kubernetes:batch/v1:CronJob    update
~   vpc-native-post-analytics-clickhouse-cron                  kubernetes:batch/v1:CronJob    update
~   vpc-native-personalized-digest-cron                        kubernetes:batch/v1:CronJob    update
~   vpc-native-user-profile-analytics-history-clickhouse-cron  kubernetes:batch/v1:CronJob    update
~   vpc-native-validate-active-users-cron                      kubernetes:batch/v1:CronJob    update
~   vpc-native-update-tags-str-cron                            kubernetes:batch/v1:CronJob    update
~   vpc-native-sync-subscription-with-cio-cron                 kubernetes:batch/v1:CronJob    update
-   vpc-native-api-db-migration-f40ae263                       kubernetes:batch/v1:Job        delete
~   vpc-native-update-current-streak-cron                      kubernetes:batch/v1:CronJob    update
~   vpc-native-bg-deployment                                   kubernetes:apps/v1:Deployment  update
~   vpc-native-temporal-deployment                             kubernetes:apps/v1:Deployment  update
~   vpc-native-update-achievement-rarity-cron                  kubernetes:batch/v1:CronJob    update
~   vpc-native-user-profile-updated-sync-cron                  kubernetes:batch/v1:CronJob    update
~   vpc-native-clean-stale-user-transactions-cron              kubernetes:batch/v1:CronJob    update
~   vpc-native-channel-digests-cron                            kubernetes:batch/v1:CronJob    update
+   vpc-native-api-clickhouse-migration-8e5b54a6               kubernetes:batch/v1:Job        create
~   vpc-native-materialize-yearly-best-post-archives-cron      kubernetes:batch/v1:CronJob    update
~   vpc-native-private-deployment                              kubernetes:apps/v1:Deployment  update
-   vpc-native-api-clickhouse-migration-f40ae263               kubernetes:batch/v1:Job        delete
~   vpc-native-ws-deployment                                   kubernetes:apps/v1:Deployment  update
... and 15 other changes

[rebelchris]

Related PRs (deploy in this order):

1. dailydotdev/mimir#47 — source_id index migration
2. feat: add searchSourcePosts query for squad text search #3996 — searchSourcePosts GraphQL query
3. feat: add in-squad post search apps#6301 — squad page search UI