chore: audit test suite for efficiency and redundancy

[j4th]

Context

The test suite has grown to ~1200 tests across 4 tiers (unit, integration, live, quick). Full mise run check takes ~3 minutes and check:full ~4-5 minutes. As we add more providers (Spicerack, MTGGoldfish, etc.), test count and runtime keep climbing. Time for a periodic audit.

Areas to Review

1. Test runtime profiling

• Run pytest --durations=30 to identify the slowest tests
• Are any unit tests doing unnecessary work (e.g., redundant fixture setup, repeated cache clearing)?
• Can slow service tests share fixtures more efficiently?

2. Redundancy between tiers

• Do integration tests (tests/integration/) duplicate coverage already in provider unit tests?
• Do live tests (tests/live/) overlap with integration tests beyond what's needed for real-world regression?
• Are there unit tests that test the same code path through slightly different inputs without adding value?

3. Provider test patterns

• Each new provider (EDHREC, Moxfield, Spicerack, MTGGoldfish) follows the same test pattern. Are we testing boilerplate (e.g., ToolError wrapping, response_format variants) redundantly across providers?
• Could shared parametrized fixtures reduce duplication for common patterns (lifespan init, error handling, attribution lines)?

4. Fixture overhead

• conftest.py clears all service caches via autouse fixture. Is the clearing list growing unwieldy?
• Are HTML/JSON fixture files larger than needed? Could we trim captured fixtures to only the fields tests actually assert on?

5. Workflow test efficiency

• Workflow tests use AsyncMock — these should be fast. Are any accidentally doing real work?
• test_workflow_server.py tests tool registration — does this overlap with test_orchestrator_e2e.py?

6. testmon effectiveness

• Is pytest-testmon correctly detecting affected tests, or is it re-running too many?
• Are there test files that testmon always marks as affected due to broad imports?

Outcome

• Identify and remove redundant tests
• Speed up the slowest tests
• Document any test patterns that should be standardized
• Target: keep mise run check under 2 minutes as the suite grows

Priority

Low — not blocking anything, but good hygiene to do periodically as the project scales.