Public sparse/field admission

Base 70dfb1f55e4cb2570d5a78a497be5828a203087b, Strata 56aedb2d12b3126c601eb333419136d403614dbb; input closure 47bffad98aa5a820aab3bf02d2d19d375bcc0ba76e07d24268b35d39b9426250. Inventory includes new untracked compiler files. Parent audit retains the unchanged historical gate/probe evidence.

The private Csr view admits the complete immutable partition and all column indices. Every application checks vector lengths before output clearing, prefetch or unchecked access. Chebyshev validates every dimension before coefficient allocation and reuses one admitted view. Field entry points enforce nonempty powers of two and exact multilinear coordinate counts before private kernels or recursion. Sparse arithmetic, floating-point operand order, Bessel scaling and field arithmetic are unchanged. Root inspected the complete guard before formerly unsafe malformed-input tests were executed.

cargo test -p acpu --lib --tests --locked --offline passes 187 tests with one existing ignored, in both debug and release; the latter command adds --release. The new public integration target contains five tests: 30 malformed CSR calls through both operations, 51 Chebyshev shape/partition/index calls, field shape/coordinate cases and independent valid controls for rectangular sparse arithmetic and two-element heat evolution. All malformed calls require the appropriate panic and unchanged outputs/scratch. The huge-order malformed Chebyshev cases establish shape-error precedence.

Strict library/test Clippy remains red on historical production and test hygiene; full diagnostic text is retained. Independent review and the separate mechanical hygiene unit follow. This unit does not resolve the measured Chebyshev numerical overflow and does not establish publication readiness.