fix(auth): register vertex in PROVIDER_REGISTRY for auxiliary clients

[Bartok9]

Summary

• Add a static ProviderConfig for vertex (auth_type=vertex) to PROVIDER_REGISTRY.
• Restores auxiliary-task LLM clients (title generation, compression, vision, session search, curator) on Vertex-only deployments.

Motivation

Closes #61852.

Main chat already worked: resolve_runtime_provider special-cases Vertex OAuth/ADC. Auxiliary work goes through resolve_provider_client, which looks up PROVIDER_REGISTRY. Plugin auto-promotion only admits auth_type=api_key providers, so vertex was missing and the resolver returned (None, None) — silent failure on every aux task when no aggregator fallback keys exist.

The fix mirrors Bedrock static aws_sdk registration so the existing auth_type == vertex branch in auxiliary_client can run.

Verification

• python3 -m pytest tests/agent/test_vertex_provider_registry.py -q — 5 passed
• Did NOT change: runtime_provider vertex path, vertex_adapter token minting, or api-key plugin auto-promotion rules

[teknium1]

Thanks for tracing this to the registry boundary. Current main confirms the premise: hermes_cli/auth.py:455 excludes Vertex from auto-promotion, while agent/auxiliary_client.py:4858 returns (None, None) before the existing Vertex branch at agent/auxiliary_client.py:5012 can run.

Problems

• tests/agent/test_vertex_provider_registry.py:12 imports pytest, but the new test module does not use it.

Suggested changes

• Remove the unused pytest import.

Automated hermes-sweeper review.

[teknium1]

pytest is not used in this module; remove this import.

[Bartok9]

Thanks for the review! Removed the unused pytest import from tests/agent/test_vertex_provider_registry.py (the module uses unittest.mock only). Pushed as a4eb53fdd5. Local run: 6 passed.

[Bartok9]

Rebuilt onto latest main via patch re-apply (force-push). Please re-run CI.

— Bartok9 public PR hygiene 2026-08-01