Complete Model Target API fidelity and refresh credentials - #3451

What changed

• replace the suspended CI credential set used by TestSuccess
• regenerate all 100 encrypted and iCloud credential files with a complete 23-field schema
• request standard, advanced, State-Based, and Advanced State-Based Model Target scopes
• add OAuth password grants, scoped tokens, route-level scope enforcement, and the OAuth client-credentials management API to both mock backends
• match current Vuforia validation errors, State-Based behavior, shared standard/advanced UUID routing, status responses, and generated download shape
• return deterministic full-dataset.zip archives containing MTDataset.dat and MTDataset.xml
• move previously mock-only behavior into verified tests against real Vuforia and both mock backends

Why

CI slot 1 returned Vuforia 403 ProjectSuspended, blocking every open PR. The previous Model Target credentials were revoked and lacked advanced and State-Based scopes, leaving much of the mock's behavior unverified.

Validation

• decrypted and schema-checked all 100 encrypted secret files: 23 fields in every file, with all new Model Target fields present
• synchronized 100 iCloud ci_secrets files to the same schema
• obtained fresh OAuth tokens and exercised standard, advanced, State-Based, and credential-management routes against real Vuforia
• verified real standard generation, completed status fields, and full-dataset.zip through the advanced status/download routes
• tests/mock_vws/test_model_target_web_api.py: 747 passing before the credential-management addition; all added lifecycle tests pass against all three backends
• expanded Model Target and backend usage run: 854 passed, 2 skipped; the two subsequently corrected failures pass individually
• tests/mock_vws/test_query.py::TestSuccess: 21 passed, including real Vuforia
• all pre-commit and pre-push hooks pass, including Mypy, Pyright, Ty, and Pyrefly

Closes #2114
Closes #3192
Closes #3193
Closes #3194
Closes #3195
Closes #3196
Closes #3202
Closes #3344
Closes #3345
Closes #3348
Closes #3441
Closes #3444