Add Atlas Cloud model aliases

[binyangzhu000-sudo]

Summary

• add Atlas Cloud model aliases for QuantMind configs (atlascloud/, atlas-cloud/, atlas/)
• resolve Atlas Cloud aliases through the Agents SDK LiteLLM adapter with ATLASCLOUD_API_KEY and the OpenAI-compatible base URL
• wire the resolver into paper summary, paper structure, and agentic retrieval SDK agent creation
• add .env.example entries and focused tests for alias resolution and structure-provider integration

Validation

• python -m pytest tests/configs/test_base.py tests/flows/test_structure.py tests/mind/test_retrieval.py tests/flows/test_paper.py::SummaryMapReduceTests -q --no-cov (36 passed)
• python -m ruff check quantmind/configs/base.py quantmind/configs/__init__.py quantmind/flows/_paper_summary.py quantmind/flows/paper/_structure.py quantmind/mind/retrieval.py tests/configs/test_base.py tests/flows/test_structure.py
• python -m ruff format --check quantmind/configs/base.py quantmind/configs/__init__.py quantmind/flows/_paper_summary.py quantmind/flows/paper/_structure.py quantmind/mind/retrieval.py tests/configs/test_base.py tests/flows/test_structure.py
• git diff --check
• Atlas Cloud live /v1/models returned 120 models and confirmed qwen/qwen3.5-flash and deepseek-ai/deepseek-v4-pro

No README changes.

[binyangzhu000-sudo]

Thanks for the review signal. I pushed follow-up commit 0e442f4 merging current master into this branch and resolving the conflicts around the paper semantic configuration rename while preserving the Atlas Cloud model alias adapter.

Validation:

• uv run --python 3.11 --extra dev pytest -> 432 passed, coverage 85.68% (>=75%)
• uv run --python 3.11 --extra dev ruff check quantmind/configs/__init__.py quantmind/configs/base.py quantmind/flows/_paper_summary.py quantmind/flows/paper/_structure.py quantmind/mind/retrieval.py tests/configs/test_base.py tests/flows/test_structure.py -> passed
• uv run --python 3.11 --extra dev basedpyright quantmind/configs quantmind/flows quantmind/mind -> 0 errors
• git diff --check origin/master...HEAD -> passed

Notes:

• No README, docs, logo, sponsor, credits, or partner content was changed by this follow-up.