v0.10.0-rc1 — GP Bikes attach + reload (test)

FrostMod now attaches to GP Bikes and reloads its mods, alongside MX Bikes.

Run frostmod.exe --game gpb (or --process gpbikes.exe). Drop a .pkz into
Documents\PiBoSo\GP Bikes\mods\tracks, press R, and it should appear in-game without a
restart — the same as MX Bikes.

Why this is a pre-release

The GP Bikes offsets were recovered by static analysis of an unpacked gpbikes.exe and
have not been confirmed under a debugger, and MX Bikes has not been regression-tested
against the refactor. The Windows build passes CI, so it compiles and links — but nothing
here has been run.

frostmod.exe's update check reads releases/latest, which excludes pre-releases, so
nobody on v0.9.11 is offered this. Download it deliberately, or don't.

Two things to check before this is promoted to a full release:

1. Confirm RVA_CONTENT_INIT (0xfb650) and RVA_SCAN_FOLDER (0x18f150) under x64dbg.
2. Regression-test MX Bikes — the refactor touched its path too. GP Bikes gaining a
   broken feature is an inconvenience; MX Bikes losing a working one is not.

What's in it

• Per-title offsets table; MX Bikes' values are unchanged.
• GP's scanner prologue is byte-for-byte identical to MX's, so the signature-with-delta
  fallback that survives a game update works for either title unchanged.
• Features whose offsets are MX-Bikes-only now stay off on other titles instead of
  firing at addresses that mean nothing there. The server-browser filter is the one that
  matters — its hook writes a jump at an address that is unrelated code on GP Bikes.
• --update refuses to run while either game is open, not just MX Bikes.

Full derivation and what remains: tasks/gp-bikes-port.md. Server-browser filter, master
protocol and direct connect are still MX Bikes only.