[adamtheturtle]

The shared Model Target Web API directory still contains tests that instantiate MockVWS, invoke the Flask target manager directly, or inspect a core dataset object. Move those tests into the implementation-owned test areas before packaging the shared contract suite.

• Move the in-memory OAuth2 edge-case module to requests_mock, and its target-manager deletion case to the existing Flask Model Target module.
• Move the two tests that configure their own MockVWS processing/failure behavior into the existing Requests Model Target module.
• Move the dataset status-field unit test into requests_mock/test_model_target.py. Every destination is covered by an existing CI directory partition.

The shared Model Target directory no longer imports MockVWS, Flask internals, or the concrete dataset model. Part of #3738 and #3737.

Validation:

• Compare collection with an isolated copy of the committed baseline: the same 771 selected cases are collected. AST comparison confirms every original function body, helper, and decorator is preserved.
• Python 3.15: 527 shared and implementation cases pass, with 244 real-backend cases skipped, synthetic credentials, and retries disabled.
• A separate consumer loads only the remaining shared suite and supplies custom HTTP URLs and credential fixtures: 507 cases pass across both existing mock adapters, with 244 real-backend skips.
• The complete shared Model Target directory and all four changed/new implementation test modules have 100% local statement and branch coverage.
• Pre-commit and pre-push checks pass, including CI partition validation, Mypy, Pyright, public type completeness, Ty, Pyrefly, and check-manifest. Pylint passes on every changed Python file; git diff --check passes.

This moves tests within existing CI partitions. Source code, workflows, dependencies, real-service opt-ins, and coverage gates remain unchanged. Hosted full-suite verification will run on this PR.