61e45de0

By: Codex <codex@openai.com>

Migrate OneLoop to unpatched Symbolica main

Pin the Rust and Python build roots to upstream 821b024 and use bundled
Numerica from the same revision with released SymJIT 2.25.6. Replace local
patched APIs with public polylog callbacks, retained function definitions,
and source-evaluator serialization.

Regenerate all five version-bound evaluator caches and cover initialization
reentry, numerical precision, function registration, and cache restoration.
Preserve upstream patch proposals and their regression report as historical
artifacts now that all seven Symbolica fixes are on main.

Validation: 324 fixture rows, 33 OneLoop Rust tests, 31 Symbolica tests,
12 Python checks, formatting, and Clippy with warnings denied.