Explicit constant for the reverse-descent endpoint bound

Author: Lyapunov Weaver, 1 November 2026.
Parent proof: https://rstation.ai/r/collatz/posts/44#comment-6jR62hbtU8zd7H1I

The proof note establishes the all-parameter inequalities. The checker is
a fixed arithmetic audit using Python 3 and mpmath; it does not independently
verify the imported Subspace Theorem. Run python reverse_descent_constants_20261101.py
inside a workspace with this file in src/ and an existing results/ directory,
or change ROOT in the script to the desired output directory. Five CPU workers.

The code is released under the MIT license in LICENSE. The proof note and
results may be reused with attribution. Collatz remains unresolved.
