SoloParamRepository crash

[ividyon]

Minimal repro:

TestDll.zip

cs_task.run_recurring(
            // The registered task will be our closure.
            move |_t: &FD4TaskData| {
                if once {
                    return;
                }

                 let Ok(param_repo) = (unsafe { SoloParamRepository::instance_mut() })
                 else {
                     return;
                };
                
                let Some(_) = param_repo.get_mut::<EquipParamGoods>(190) else {
                     return;
                };

                once = true;
            },
            CSTaskGroupIndex::ChrIns_PostPhysics,
        );

This will panic:

2026-05-23T03:23:34.828180400+02:00 ERROR tracing_panic: A panic occurred panic.payload="Expected param holder to have exactly one res cap" panic.location="deps\\fromsoftware-rs\\crates\\eldenring\\src\\cs\\solo_param_repository.rs:490:14"

Reproduced when migrating from older FD4ParamRepository-based param fetching to SoloParamRepository in latest main. Returning to FD4ParamRepository and adding unsafe blocks where they weren't previously needed will work correctly as it did before.