NPC Vector3 input APIs crash or receive <0,0,0> due to native proxy marshalling mismatch

[AgustinIbanez00]

Npc.SetPosition(...) crashes the server with a segmentation fault (SIGSEGV / exit 139), and INpcService.AddPointToPath(...) silently stores <0, 0, 0> instead of the point passed in. Both stem from the same cause: the native proxies for these NPC APIs declare their Vector3 input argument as const Vector3& (a pointer at the ABI boundary), while the source-generated managed P/Invoke marshals Vector3 by value.

Affected APIs:

• Npc.SetPosition — crashes the server.
• INpcService.AddPointToPath — stores <0, 0, 0>; an NPC driven with MoveByPath glides to the world origin instead of following the path.
• Npc.Shoot, Npc.AimAt, Npc.AimAtPlayer, INpcService.HasPathPointInRange — same Vector3-input mismatch.

Minimal reproduction:

// spawned NPC, valid path service
npc.SetPosition(new Vector3(1260f, -2342.25f, 16f), true); // (1) crashes the server (SIGSEGV)

var path = npcService.CreatePath();
npcService.AddPointToPath(path, new Vector3(1260.875f, -2335.375f, 16.066f), 1f);
npcService.GetPathPoint(path, 0, out var stored, out _);    // (2) stored == <0, 0, 0>

Observed behavior:

• SetPosition → server exits with code 139 (SIGSEGV) before the next line runs.
• AddPointToPath → GetPathPoint reads back <0, 0, 0>; MoveByPath drives the NPC straight to the world origin.

Expected behavior:

• SetPosition moves the NPC to the requested coordinates.
• AddPointToPath stores the exact point; MoveByPath follows the path.

Notes:

• Proxies already declared by-value (e.g. Npc.MoveTo) are unaffected and always worked.
• Native-only defect: the managed assemblies are correct; the fix is in src/sampsharp-component/proxies/api.cpp.
• Seen on Linux with 1.0.0-prerelease2.