refactor: extract data fixes into dedicated package

internal/database/fixes/registry.go

@@ -0,0 +1,25 @@
+package fixes
+
+import (
+	"context"
+	"database/sql"
+	"sort"
+)
+
+type Fix struct {
+	ID    string
+	Apply func(ctx context.Context, sqlDB *sql.DB) error
+}
+
+var registered []Fix
+
+func Register(fix Fix) {
+	registered = append(registered, fix)
+}
+
+func All() []Fix {
+	out := append([]Fix(nil), registered...)
+	sort.Slice(out, func(i, j int) bool { return out[i].ID < out[j].ID })
+	return out
+}
+