Bug fixes and auto-import of snappy_16_knots.

Highlights include:

1. An array of tools related to ribbon concordances and slice obstructions, drawn from [Dunfield-Gong 2025].

2. The upper bounds on the bridge number of a link from [Blair-Kjuchukova-Pfaff].

Minor bugfixes and infrastructure improvements.

Improves compatibility with forthcoming SageMath 10.1.

Selected speedups, code cleanup (thanks to Frédéric Chapoton), and extended Tangle (thanks to Kyle Miller).

Major speedup in Link simplification code for large (100+ crossing) links.

• Convention changes: Sign of knot signature (now positive knots have
  negative signatures), choice of braid generators (now positive
  generators give positive crossings).

• Faster "local" algorithm for the Jones polynomial

• Incorporates Zoltán Szabó's program for computing knot Floer homology.

• Link now accepts DT codes.