* test: delete unconditionally skipped legacy tests
* test: move whole-unit legacy test files into tests/unit
* test: keep moved legacy tests free of import-time global state
* test: keep the module-level invocation scan pointed at tests/local_testing
* ci: drop the agent_testing CircleCI job emptied by the move
* test: fix moved-test isolation and router coverage
* test: add Tinyfish search package marker
* test: isolate moved tests from logger state leaks
* test: isolate Helicone logging fixture state
* test: isolate Vertex pass-through credentials between moved tests
* test: cancel S3 periodic flush tasks started by moved tests
* ci: restore CircleCI assistant test selection after move
* test: prevent Datadog datetime import shadowing
* ci: drop the litellm_assistants_api_testing CircleCI job emptied by the move
* test: deduplicate imports in rebased unit tests
* test: remove duplicate passthrough router patch import
* test: remove moved legacy source files after rebase
* test: align moved tests with rebased main
* test: carry main's legacy-file edits into moved destinations
* test: make the moved cost map fallback tests assert the fetch and the backup
The four fallback cases only checked the result was non-empty, so they still
passed with integrity validation disabled. They now inject a mock client, assert
one fetch happened, and assert the result is exactly the local backup with the
fallback reason recorded.
---------
Co-authored-by: yuneng <yuneng@berri.ai>
