Exclude integration tests from default pnpm test; opt-in via test:integration

The Redis-publisher integration test uses testcontainers to spin up a real
Redis. On the Gitea CI runner, `container.start()` hangs (likely image-pull
delay or restricted Docker access), and the 60s beforeAll timeout fails the
suite even though both tests ultimately would skip. The skip-on-error path
only fires when start() throws, not when it times out.

Fix: separate unit tests (default) from integration tests (opt-in). The
default `pnpm test` now runs only `test/**/*.test.ts` excluding
`*.integration.test.ts`. A new `pnpm test:integration` script runs them
via `vitest.integration.config.ts` with generous hook/test timeouts for
container startup.

CI runs `pnpm test` and is unaffected by Docker availability. Integration
tests can be run locally or in a future CI job that explicitly provisions
Docker.

package.json

@@ -12,6 +12,7 @@
     "start": "node dist/main.js",
     "test": "vitest run",
     "test:watch": "vitest",
+    "test:integration": "vitest run --config vitest.integration.config.ts",
     "lint": "eslint .",
     "format": "prettier --write .",
     "typecheck": "tsc --noEmit"