Add FLAS to leaderboard

[Lunamos]

Summary

• Add a "Beyond rank-1" subsection under the rank-1 steering leaderboard in the README, with FLAS (Flow-based Activation Steering) as a first entry

• Why a separate section: FLAS is not a rank-1 intervention. Rather than computing one steering vector per prompt and adding it at every position (as HyperSteer does), it integrates a learned velocity field over multiple steps, where the displacement is re-evaluated from the current activation at each step and differs across token positions. Recent methods like AcT and K-Steering also relax these restrictions, so this class may keep growing.

• Scores follow the main table's setting (held-in harmonic mean, layer 20, Concept16k): 1.025 on Gemma-2-2B-IT, 1.185 on Gemma-2-9B-IT, at a single fixed flow time with no per-concept tuning

• Left index.html untouched for now — happy to mirror the section there too if you'd like

• Website: https://flas-ai.github.io

• Paper: https://arxiv.org/abs/2605.05892

• Code: https://github.com/flas-ai/FLAS

• Models: https://huggingface.co/flas-ai

Possible follow-ups (if there's interest)

• Train a rank-1-constrained FLAS-r1 for the main table, to see how much of the gain survives the restriction