e9031dcd

By: ValentinHirschi <valentin.hirschi@gmail.com>

keep shared threshold geometry on representative cut samples

Shared overlap groups retain only the representative MomentumSample consumed by
existence checks, SOCP center construction and foreign-cut partition factors.
Raised LU derivative packets remain with their physical cut owners. Update the
existing foreign-cut/raised fixtures and record the next generic star-map and
acceptance boundaries. No threshold metadata or projection solver is changed.

Validation: cargo check -p gammalooprs --tests; focused nextest foreign-cut
radial-derivative and generalized raised-cross-section component/roundtrip tests
(2 passed); cargo clippy -p gammalooprs --all-targets; formatting and diff checks.

User prompts:
"Continue as planned, but re-read the plan, and establish how to best orchestrate progress on both front of amplitude surface advanced sampling, but also the overall goal of cross-section advanced sampling, that must eventually apply to GL638 and demonstrate improvement there."

"(continue as planned, but remember that for being able to quickly generate states for testing, specifying ot one orientation may help. But ultimately, things must be tested end-to-end on all orientations)"

Timeline