[SirFancyBacon]

Summary

Entering some interiors, Carl's house in Norune among them, crashed in CFrame::GetLWMatrix. SetCameraPos kept the active camera as a pointer into a list that is freed every frame. It now keeps the camera by its place in that list, and the list lives on the stack again.
fixes #214
fixes #217

Cause

• The core dump's backtrace: CFrame::GetLWMatrix ← CFrame::GetWorldPosition ← SetCameraPos ← EditInLoop.
• SetCameraPos (port/src/edit_in.cpp) rebuilds the interior's camera list every frame from the parts' camera markers, and the file-static active_camera remembers which one the player last stood in, from one frame to the next.
• In retail the list is a local array, so active_camera points into the stack. That only holds because the list sits at the same address every frame and is refilled before active_camera is read.
• 98580bd moved the list into a std::make_unique allocation made on each call. The next frame's allocation can land elsewhere, leaving active_camera pointing at freed memory, and GetWorldPosition then follows a garbage parent pointer. Whether it crashes depends on the allocator, which is why only some interiors show it.

Fix

• active_camera is the camera's index in the list, -1 for none, instead of a pointer. EditInInit resets it to -1, where it reset the pointer before.
• The list is a std::array<INTERIOR_CAMERA, 8> on the stack again, so there is no allocation each frame. The cap of eight and the early returns from 98580bd are kept.
• The index is checked against this frame's list before it is used. Retail never needs that, since an interior's camera count doesn't change while the player is in it, but a stale index can then never read a slot that wasn't rebuilt.
• Two commits: the first restored a fixed address for the list (a static array), the second replaces that with the index. They can be squashed.

Testing

• In game (Linux, Flatpak): Carl's house, which crashed on entry every time, now loads and plays normally.
• Builds with no new warnings; all tests pass but the two GfxValidation ones, which need a Vulkan validation layer the SDK lacks.