Survivor harness, quiver and arrows weirdness

# Describe the bug

So arrows are supposed to fit into a survivor harness, because it has a pocket of appropriate length and volume. However, if I try to pick up an arrow while wearing the harness, it only gives me an option to (w)ield it. If it try to (i)nsert an arrow into a harness, it does not appear in the item list. However, if I equip a quiver with arrows and start picking up more arrows, once the quiver fills up, arrows do go into the harness. I can then drop the quiver and arrows will stay in the harness. However, when I save and reload, I get an error about items being in an incompatible container and all arrows inside the harness get destroyed. Another strange thing is that I can't put arrows into a harness, but I can put a quiver WITH arrows into a harness. How does this work?

# Steps To Reproduce

1) Equip survivor's harness
2) Try to pick up arrows (fails)
3) Equip an empty quiver
4) Pick up 100 arrows (60 will go into a quiver and 40 will go into the harness)
5) Take quiver off

# Expected behavior

I expect the harness to be either able to fit arrows accoring to its stats, or state why I can't put arrows in it. This behaviour should not depend on whether I also have quiver equipped or not.

# Screenshots

I can attach a screenshot or a savegame if needed.

# Versions and configuration

I'm running the latest experimental build. I can provide better info if needed.

# Additional context

Reproduce the survivor harness, quiver, and arrow steps, including saving and reloading after arrows enter the harness. Start by tracing item insertion and container-compatibility handling for direct arrows versus a quiver containing arrows. Done means the harness behavior is consistent with its capacity and reload no longer destroys valid contents, with regression coverage for the reported sequence.

Written by the indexing model from the issue text.