Fix stale service references and test imports

[Abivankenobi]

Human Summary

While running backend tests, I found references to request/response models that no longer exist. This PR updates those references to the current models and aligns tests with the active service implementations.

AI Summary

Fix stale service references in tests and align a legacy cache service with the current request/response models.

Changes

• Update test imports to use the active core service modules:

  • app.services.core.cache
  • app.services.core.database

• Replace stale SearchScrapeRequest / SearchScrapeResponse references in app/services/cache.py with the current UnSearchRequest / UnSearchResponse models.

• Replace deprecated Pydantic .dict() usage with .model_dump().

Context

While running the backend test suite, test collection failed due to references to removed SearchScrape* models. Investigation showed that the active codebase uses UnSearchRequest and UnSearchResponse, while some stale references remained in tests and the legacy cache service.

Validation

• Verified backend test collection after the import updates.
• Confirmed that the updated imports reference the active service implementations.
• No API routes or production business logic were modified.