Update upstream to v159.6 and regenerate patch set

[Copilot]

This updates the repository’s upstream base to v159.6 and aligns loader metadata with the same game version. It also refreshes generated patch artifacts so the patch-first workflow remains consistent after the upstream move.

• Upstream bump (Arc + work)

  • Ran the upstream update flow against tag v159.6, moving both submodule pointers to the new upstream commits.
  • Replayed the existing patch chain on top of the new base and resolved replay conflicts where upstream changed overlapping areas.

• Version alignment in mod metadata

  • Updated loader metadata to target the new upstream build:

  minGameVersion: "159.6"
  

• Patch regeneration consistency

  • Re-generated patches/arc, patches/picked, and patches/client from the updated Arc/ and work/ histories so patch files match the new upstream baseline.
  • Kept the upstream update + regenerated patches + metadata version alignment in the same amended commit, per request.