feat(nestjs-signed-url): wire gcs client boundary

[TorinAsakura]

Task

• Close [Feature] Make GCS signed URL provider configurable #384

How to verify

Main scenario

1. Context: @atls/nestjs-signed-url GCS module wiring through @atls/nestjs-gcs-client
   Action: import GcsClientModule.register() and inject GcsClientFactory into SignedUrlModule.gcsAsync(...).
   Expected result: GcsSignedUrlSigner uses the Storage returned by the public GCS client factory and maps write URL options to GCS GetSignedUrlConfig.

Additional scenario

1. Context: shared GCS client dependency boundary
   Action: typecheck and build @atls/nestjs-signed-url and @atls/nestjs-gcs-client under Node 22.
   Expected result: both packages compile against the same @google-cloud/storage version and the signed-url package does not duplicate GCS client configuration fields.

Proofs

• mise x node@22.22.3 -- yarn format packages/nestjs-gcs-client/package.json packages/nestjs-signed-url/package.json packages/nestjs-signed-url/gcs/tests/module.test.ts: passed
• mise x node@22.22.3 -- yarn lint packages/nestjs-signed-url/gcs/tests/module.test.ts: passed
• mise x node@22.22.3 -- yarn typecheck packages/nestjs-signed-url: passed
• mise x node@22.22.3 -- yarn typecheck packages/nestjs-gcs-client: passed
• mise x node@22.22.3 -- yarn test unit --test-reporter=tap from packages/nestjs-signed-url: 17 tests passed
• mise x node@22.22.3 -- yarn run build from packages/nestjs-signed-url: passed
• mise x node@22.22.3 -- yarn run build from packages/nestjs-gcs-client: passed
• mise x node@22.22.3 -- yarn check: passed
• git diff --check: passed