fix: revert DB driver to static imports, fix test regressions

- Revert createRequire() for DB drivers — require() can't resolve .ts
  files in Vitest, breaking 49 test suites
- Make cache invalidation fail-safe via try-catch around revalidateTag
  (throws outside Next.js context: tests, tasks service, websocket)
- Fix 6 integration test imports: barrel no longer exports concrete
  classes, point tests at direct source paths
- Fix Redis cache handler lint errors: remove non-null assertions,
  suppress __NEXT_BUILD_ID underscore warning

packages/core/src/infrastructure/db/drivers/index.ts

@@ -1,15 +1,12 @@
-import { createRequire } from "node:module";
-
 import { DB_CASING } from "../constants";
-import { dbEnv } from "../env";
+import { createDbMapping } from "../mapping";
+import { createMysqlDb } from "./mysql";
+import { createPostgresDb } from "./postgresql";
 import type { SharedDrizzleConfig } from "./shared";
 import { WinstonDrizzleLogger } from "./shared";
+import { createSqliteDb } from "./sqlite";
 
-const require = createRequire(import.meta.url);
-
-export type Database<TSchema extends Record<string, unknown>> = ReturnType<
-  typeof import("./sqlite").createSqliteDb<TSchema>
->;
+export type Database<TSchema extends Record<string, unknown>> = ReturnType<typeof createSqliteDb<TSchema>>;
 
 export const createSharedConfig = <TSchema extends Record<string, unknown>>(
   schema: TSchema,
@@ -21,15 +18,10 @@ export const createSharedConfig = <TSchema extends Record<string, unknown>>(
 
 export const createDb = <TSchema extends Record<string, unknown>>(schema: TSchema) => {
   const config = createSharedConfig(schema);
-  // ponytail: conditional require — only the configured driver is loaded.
-  // Ceiling: all 3 stay on disk for runtime driver switching; only loaded graph shrinks.
-  const driver = dbEnv.DRIVER ?? "better-sqlite3";
-  switch (driver) {
-    case "mysql2":
-      return (require("./mysql") as typeof import("./mysql")).createMysqlDb(config);
-    case "node-postgres":
-      return (require("./postgresql") as typeof import("./postgresql")).createPostgresDb(config);
-    default:
-      return (require("./sqlite") as typeof import("./sqlite")).createSqliteDb(config);
-  }
+
+  return createDbMapping({
+    mysql2: () => createMysqlDb(config),
+    "node-postgres": () => createPostgresDb(config),
+    "better-sqlite3": () => createSqliteDb(config),
+  });
 };