Declare documented API public (unlock downstream ExplicitImports)

[ChrisRackauckas-Claude]

Please ignore this PR until reviewed by @ChrisRackauckas. Opened at @ChrisRackauckas's request (a maintainer/top-contributor of ArrayInterface).

What

ArrayInterface exports nothing — its entire user-facing API is reached via ArrayInterface.foo. As a result, downstream packages must maintain ExplicitImports non-public allow-lists for names that are documented API but were never declared public. For example, SciMLStructures.jl#71 ignores restructure and has_trivial_array_constructor, noting they are "documented API but ArrayInterface has not adopted the public keyword."

This PR declares every documented, ArrayInterface-owned API name with the Julia 1.11+ public keyword so downstream packages (SciMLStructures, NonlinearSolve, and others) can drop those allow-lists.

The declaration is version-gated (@static if VERSION >= v"1.11.0-DEV.469") and eval'd via Expr(:public, ...) because the public keyword only parses on Julia 1.11+, while the package's compat floor is Julia 1.10.

Selection criteria

A name was made public iff it (a) carries a docstring in src/, (b) appears in the docs/src/*.md API pages, (c) is defined in ArrayInterface (not a re-export), and (d) is not already exported. The docstring set and the docs-page set were cross-referenced and match exactly (42 names). Internal helpers (underscore-prefixed, parameterless_type, stride_preserving_index, the index/device structs and type aliases, etc.) and the StaticArrayInterface-only names (known_*, stride_rank, contiguous_axis, …, which live in a separate package) were left non-public.

madePublic (42)

• conversions (docs/src/conversions.md): aos_to_soa, promote_eltype, restructure, safevec, has_trivial_array_constructor
• indexing traits (docs/src/indexing.md): can_avx, can_change_size, can_setindex, fast_scalar_indexing, ismutable, ndims_index, ndims_shape, defines_strides, ensures_all_unique, ensures_sorted, indices_do_not_alias, instances_do_not_alias, device
• allowed indexing: allowed_getindex, allowed_setindex!
• indexing type buffers: ArrayIndex, GetIndex, SetIndex!
• linear algebra (docs/src/linearalgebra.md): zeromatrix, undefmatrix, issingular, bunchkaufman_instance, cholesky_instance, ldlt_instance, lu_instance, qr_instance, svd_instance
• sparse arrays (docs/src/sparsearrays.md): isstructured, findstructralnz, has_sparsestruct, fast_matrix_colors, matrix_colors
• wrapping (docs/src/wrapping.md): is_forwarding_wrapper, buffer, parent_type
• tuples (docs/src/tuples.md): flatten_tuples, map_tuple_type

skipped (with reason)

• already exported — none; ArrayInterface exports nothing, so no name was both exported and public.
• undocumented internal helpers (no docstring, not in docs): parameterless_type, __parameterless_type, stride_preserving_index (block-comment only, not a docstring), diaganyzero, noalloc_diag, _cycle, _device, _not_pointer, _new_field_positions, _fl1, _indices_do_not_alias, _defines_strides
• internal types / aliases / consts (not in docs): VecAdjTrans, MatAdjTrans, UpTri, LoTri, MatrixIndex, VectorIndex, BidiagonalIndex, TridiagonalIndex, BandedMatrixIndex, ColoringAlgorithm, AbstractDevice, AbstractCPU, CPUPointer, CPUTuple, CPUIndex, CheckParent, GPU, DEFAULT_CHOLESKY_PIVOT
• not defined here (live in StaticArrayInterface.jl): known_length, known_size, known_first, known_last, known_step, static_length, indices, offsets, strides, contiguous_axis, stride_rank, dense_dims — none of these exist in this package, so they were not invented.

Verification (run locally)

• Julia 1.10 (compat floor): package precompiles and loads cleanly; the public block is correctly skipped (version gate is false).
• Julia 1.12.6: package loads; for all 42 names Base.ispublic(ArrayInterface, name) == true and Base.isexported(ArrayInterface, name) == false. The two SciMLStructures motivators (restructure, has_trivial_array_constructor) are confirmed public. Sampled internals (parameterless_type, stride_preserving_index, MatrixIndex, BidiagonalIndex, CPUPointer, diaganyzero) confirmed to remain non-public.
• Full test suite on Julia 1.10 passes (Core 195/195, AD Integration 20/20, StaticArrays 39/39, BandedMatrices 21/21, BlockBandedMatrices 8/8, ChainRules 20/20) — Aqua included.
• Formatting: the added block matches the repo's .JuliaFormatter.toml SciML style (running the official formatter leaves the block unchanged); no bulk reformatting of unrelated code.

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 60.20%. Comparing base (83d7bc9) to head (62cb429).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #491   +/-   ##
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  Coverage   60.20%   60.20%           
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  Files          14       14           
  Lines         588      588           
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  Hits          354      354           
  Misses        234      234           

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