✨ Support wide Qiskit register comparisons

[simon1hofmann]

🤖 AI text below 🤖

Description

Support exact Qiskit interchange for unsigned comparisons between one complete
named classical register wider than 64 bits and one same-width integer literal.
Both operand orders and all unsigned equality and ordering predicates are
supported.

The implementation keeps the current MLIR representation: cbit.read
materializes the register value and arith.cmpi compares it with an integer
constant. Export recognizes this direct shape, and import emits the same
operations. Only this direct register-and-literal form bypasses the generic
64-bit limit. Computed or packed unsigned expressions and signed comparisons
wider than 64 bits remain unsupported.

Normalized unsigned literals use llvm::APInt. The Python boundary transfers
integers as unsigned hexadecimal text, preserving large positive values without
depending on Python's decimal string-conversion limit.

The branch is based directly on current main and contains one focused commit.
The Qiskit support documentation describes the direct-wide boundary.

Validation

• Built mqt-core-mlir-bindings against LLVM/MLIR 23.1.
• Passed all seven focused wide-comparison and rejection cases.
• Passed all 261 tests in test/python/test_mlir_qiskit_translation.py.
• Covered 65-, 151-, and 301-bit values, reversed operands, and Python's
  decimal digit limit.
• Confirmed computed unsigned and signed comparisons wider than 64 bits remain
  rejected.
• Regenerated stubs without a generated-file diff.
• Passed uvx nox -s lint and git diff --check.
• uvx nox -s cpp-lint -- origin/main could not start locally because this
  host does not provide the required clang-tidy 22; hosted CI remains
  authoritative for that check.

Codex assisted with the implementation, tests, branch update, review, and this
description.

Checklist

• The pull request only contains commits that are focused and relevant to this change.
• I have added appropriate tests that cover the new/changed functionality.
• I have updated the documentation to reflect these changes.
• No changelog entry is needed for this unreleased functionality.
• No migration instructions are needed.
• The changes follow the project's style guidelines and introduce no new warnings.
• The changes are fully tested and pass the CI checks.
• I have reviewed my own code changes.

If PR contains AI-assisted content:

• Any agent that created, edited, or submitted GitHub content was explicitly authorized for that scope, as required by our AI Usage Guidelines.
• Every agent-authored or agent-edited public text body begins with the visible disclosure 🤖 *AI text below* 🤖 (titles are exempt).
• I have disclosed AI assistance in the PR description.
• I confirm that I have personally reviewed and understood all AI-generated content, and accept full responsibility for it.

[burgholzer]

Thanks! Took this for a spin and it is much leaner now. Tests still pass, so I am pretty confident this is ready to go in 🚀
If you agree, feel free to merge!