refactor(controlplane,dataplane): migrate jobs and feature flags from postgres to sqlc

[jirevwe]

Migrate the last remaining database/postgres/ repository implementations to sqlc-based modules under internal/, completing the postgres-to-sqlc migration.

• Create internal/jobs/ with sqlc queries, Service implementing datastore.JobRepository (9 methods), and comprehensive tests
• Create internal/feature_flags/ with sqlc queries across 3 tables (feature_flags, feature_flag_overrides, early_adopter_features), Service implementing both fflag.FeatureFlagFetcher and fflag.EarlyAdopterFeatureFetcher, and comprehensive tests
• Update all call sites: dataplane worker, server init, API handlers, CLI utilities, and test files
• Delete database/postgres/job.go, feature_flag.go, feature_flag_fetcher.go, early_adopter_feature_fetcher.go

[convoy-engineering]

@cursoragent bugbot review

[cursor]

The GitHub CLI doesn't have write access to post comments. I'll provide the full review here instead.

Bug Review — PR #2622

Overall assessment: The migration is well-structured and functionally complete. The project compiles cleanly (go build ./... and go vet pass), all old references have been updated, and the sqlc-generated code matches the SQL queries. No critical bugs found.

Issues Found

1. [Medium] ErrJobNotCreated declared but never used — internal/jobs/impl.go:18 declares this sentinel, but CreateJob uses sqlc's :exec directive which only returns an error, never rows-affected. The old code in database/postgres/job.go checked rowsAffected < 1. Suggestion: remove the dead sentinel or switch to :execresult and add the check.

2. [Medium] feature_flags.Service re-instantiated per HTTP request in handlers — api/handlers/organisation.go calls feature_flags.New(h.A.Logger, h.A.DB) inside 7 different handler methods (lines 292, 382, 428, 488, 544, 603, 915). The old code used stateless package-level functions, so this is a minor allocation regression. Other migrated repos (configRepo, projectRepo) are initialized once. Suggestion: create ffService once at init time, matching worker.go and server.go.

3. [Low] CountPrevJobs SQL has redundant DISTINCT and COALESCE — id is a primary key (DISTINCT is a no-op) and COUNT never returns NULL (COALESCE is redundant). Carried over from old code.

4. [Low] Cursor comparison uses string ordering — FetchJobsPaginated uses id <= @cursor. Works correctly with ULIDs. Consistent with old code.

Things Done Well

• Clean compile, no stale references to deleted postgres functions
• Error sentinels properly consolidated into datastore/models.go
• Compile-time interface checks for JobRepository, FeatureFlagFetcher, EarlyAdopterFeatureFetcher
• Pagination logic correctly builds metadata before trimming the extra row
• Comprehensive test coverage for both packages
• Consistent structure with other recently migrated modules