fix(backend): harden postgres id default repair and CI coverage

Run Postgres id-sequence repair on every startup migration and add contract coverage plus a GitHub Actions Postgres job to catch schema-drift regressions before release.

go-backend/internal/store/sqlite/repository.go

@@ -1307,6 +1307,8 @@ func bootstrapSchema(db *store.DB, schemaSQL, seedSQL string) error {
 
 const currentSchemaVersion = 2
 
+var ensurePostgresIDDefaultsFn = ensurePostgresIDDefaults
+
 func getSchemaVersion(db *store.DB) int {
 	_, _ = db.Exec(`CREATE TABLE IF NOT EXISTS schema_version (version INTEGER NOT NULL DEFAULT 0)`)
 	var v int
@@ -1327,6 +1329,11 @@ func migrateSchema(db *store.DB) error {
 	}
 
 	ver := getSchemaVersion(db)
+	if db.Dialect() == store.DialectPostgres {
+		if err := ensurePostgresIDDefaultsFn(db); err != nil {
+			return err
+		}
+	}
 	if ver >= currentSchemaVersion {
 		return nil
 	}
@@ -1396,11 +1403,6 @@ func migrateSchema(db *store.DB) error {
 		return err
 	}
 
-	if db.Dialect() == store.DialectPostgres {
-		if err := ensurePostgresIDDefaults(db); err != nil {
-			return err
-		}
-	}
 	setSchemaVersion(db, currentSchemaVersion)
 	return nil
 }

go-backend/internal/store/sqlite/repository_migrate_test.go

@@ -0,0 +1,78 @@
+package sqlite
+
+import (
+	"database/sql"
+	"errors"
+	"testing"
+
+	"go-backend/internal/store"
+
+	_ "modernc.org/sqlite"
+)
+
+func TestMigrateSchemaRunsPostgresIDRepairEvenAtCurrentVersion(t *testing.T) {
+	raw, err := sql.Open("sqlite", ":memory:")
+	if err != nil {
+		t.Fatalf("open sqlite: %v", err)
+	}
+	t.Cleanup(func() {
+		_ = raw.Close()
+	})
+
+	db := store.Wrap(raw, store.DialectPostgres)
+	if _, err := db.Exec(`CREATE TABLE schema_version (version INTEGER NOT NULL DEFAULT 0)`); err != nil {
+		t.Fatalf("create schema_version: %v", err)
+	}
+	if _, err := db.Exec(`INSERT INTO schema_version(version) VALUES(?)`, currentSchemaVersion); err != nil {
+		t.Fatalf("seed schema_version: %v", err)
+	}
+
+	called := 0
+	original := ensurePostgresIDDefaultsFn
+	ensurePostgresIDDefaultsFn = func(db *store.DB) error {
+		called++
+		return nil
+	}
+	t.Cleanup(func() {
+		ensurePostgresIDDefaultsFn = original
+	})
+
+	if err := migrateSchema(db); err != nil {
+		t.Fatalf("migrateSchema: %v", err)
+	}
+	if called != 1 {
+		t.Fatalf("expected postgres id repair to run once, got %d", called)
+	}
+}
+
+func TestMigrateSchemaReturnsPostgresIDRepairError(t *testing.T) {
+	raw, err := sql.Open("sqlite", ":memory:")
+	if err != nil {
+		t.Fatalf("open sqlite: %v", err)
+	}
+	t.Cleanup(func() {
+		_ = raw.Close()
+	})
+
+	db := store.Wrap(raw, store.DialectPostgres)
+	if _, err := db.Exec(`CREATE TABLE schema_version (version INTEGER NOT NULL DEFAULT 0)`); err != nil {
+		t.Fatalf("create schema_version: %v", err)
+	}
+	if _, err := db.Exec(`INSERT INTO schema_version(version) VALUES(?)`, currentSchemaVersion); err != nil {
+		t.Fatalf("seed schema_version: %v", err)
+	}
+
+	wantErr := errors.New("repair failed")
+	original := ensurePostgresIDDefaultsFn
+	ensurePostgresIDDefaultsFn = func(db *store.DB) error {
+		return wantErr
+	}
+	t.Cleanup(func() {
+		ensurePostgresIDDefaultsFn = original
+	})
+
+	err = migrateSchema(db)
+	if !errors.Is(err, wantErr) {
+		t.Fatalf("expected error %v, got %v", wantErr, err)
+	}
+}