fix(experts): restore clinical 037330c routing

[Pandakingxbc]

Summary

• restore the server-deployed clinical-037330c clinical learning expert snapshot
• add precise Chinese professional society/specialty branch routing
• add targeted international guideline routing and retrieval budgets
• add the clinical-q-and-a fast path for ordinary educational medical questions
• align source verification, controlled B+ fallback, C-tier attribution, output validation, and regression tests
• exclude the later problematic clinical-8090383 URL-display changes

Verification

• diff -qr --exclude=__pycache__ confirms the bundled clinical expert directory exactly matches the recovered clinical-037330c snapshot
• uv run pytest tests/unit/agents/test_clinical_learning_subscription_template.py -q: 39 passed
• make all: Ruff passed, mypy passed, 2585 passed / 15 skipped / 31 deselected

Target

Hotfix PR into main, following the repository branching policy.