feat: remove legacy type proofs

[DavePearce]

This removes the use of legacy type proofs which we implemented using an inefficient horizontal byte decomposition.

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Note

Removes the legacy horizontal byte-decomposition type proofs and the “limitless” flag, always using recursive bitwidth proofs with a default max range constraint of 16, and updates sorting/lowering and tests accordingly.

• AIR Gadgets:
  • Bitwidth: Remove limitless mode and horizontal byte-decomposition path; always use recursive proof for widths > maxRangeConstraint; set default maxRangeConstraint to 16; minor panic message tweak.
  • Lexicographic Sort: Drop WithLimitless; ensure selector-bit binarity uses WithMaxRangeConstraint.
• MIR Lowering/Config:
  • Remove LimitlessTypeProofs from OptimisationConfig and usages; defaults updated (MaxRangeConstraint: 16).
  • Update range and sorted constraint lowering to use gadgets without WithLimitless.
• Tests:
  • Switch asm/bench/shf and asm/bench/stp to CheckWithFields(..., field.BLS12_377).

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