feat(idea-forge): add optional research profiles

[stanzhang]

这个 PR 做什么

Adds a validated optional research profile at the public Idea Forge entry while preserving the existing AI-conference workflow when no profile is supplied. It also includes an Alpha20 finance profile with packet-bound source citations, offline freshness, full-panel cross-review, and proposal-only planning.

为什么

Idea Forge currently hard-codes conference, public-benchmark, and online-freshness assumptions. Finance research needs to replace those four domain decisions without forking the workflow or letting an untrusted knowledge document select executable prompt control.

怎么验证的

• tests/test_research_profile.py: 22 new fixture-only cases pass; the source-card, seed-injection, two-direction, incomplete-review, and setup/install cases are red against the unfixed behavior.
• python -m pytest tests/ ar-runtime/scripts/tests/ -q: pass.
• ruff check .: pass.
• Model-reference, rendered-environment, secret-scan, release-tree, and public-knowledge checks: pass.
• Independent Standards and Spec reviews of head 0cffcbb374a43d7696ed365c6e4a871b17235871: no findings.
• No real provider, freshness-network, experiment, deployment, or order call was made.

范围自查

• 标题是单一关注点，没有用「、」「以及」串起不相干的改动
• 每个 commit 单独能通过测试，可单独 revert
• 没有夹带无关改动（顺手的重构、格式化、临时文件）
• 声称"完成"的部分看过实际运行或渲染结果，不是只读了源码

关联

无（downstream integration is tracked outside this repository）。