feat(iluvatar): enable modern Infini stack inference

[gongchensu]

Summary

• Add Iluvatar support to the modern InfiniLM stack builder in scripts/build_infini_stack.py, including InfiniRT, InfiniOps, and InfiniCCL configuration.
• Enable Iluvatar inference through canonical InfiniOps attention APIs for static attention, paged attention, and explicit FlashAttention paths.
• Route graph execution through the InfiniRT C++ segmented graph runtime.
• Add the Iluvatar operator manifest, runtime contract tests, builder tests, and usage documentation.

Motivation

The refactor/adopt-modern-infini-stack branch requires platform integrations to use the standalone InfiniRT, InfiniOps, and InfiniCCL components instead of the legacy implementations previously contained in InfiniCore.

Before this change, InfiniLM did not accept iluvatar as a model runner device, the stack builder could not configure the Iluvatar toolchain, and the attention adapters did not register the canonical InfiniOps Iluvatar providers.

This change enables the 9G-8B model on Iluvatar BI-V150 through static attention, paged attention with InfiniRT graph execution, and explicit FlashAttention with InfiniRT graph execution.

N/A - no linked issue.

Type of Change

• feat — new feature / new model
• fix — bug fix
• perf — performance improvement (no behavioral change)
• refactor — code restructuring without behavior change
• test — adding or fixing tests only
• docs — documentation only
• build / ci — build system or CI configuration
• chore — tooling, formatting, or other non-code changes
• Breaking change

Test Results of Involved Models on Supported Platforms (Please attach screenshots)

Benchmark / Performance Impact

Notes for Reviewers

CI / ChatOps

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[voltjia]

这块加个 TODO 吧，感觉老师应该不希望 InfiniLM 里面有这种东西 hhh，后面看看怎么办吧。

[voltjia]

这个文件可以本地留存一份，但是先不放到 InfiniLM 仓库里。