Integration 2026 week 21

* !4130 Add RHEL 9.8 to list of supported distributions
* !4135 fix(clang): disable default-const-init-field-unsafe
* !4118 NR UE: remove hardcoded 64KB limit for UE capability file
* !4120 bugfix: fix A3 event configuration
* !4056 restructuring of UE DLSCH code to handle 2 codewords
* !4132 Cleanup conflict leftover in doc/SW_archi.md
* !4113 move vrtsim channel and per-UE param configuration from CLI flags to config file
* !4127 Bugfix overflow uint16_t variable when FFT size is 6144
* !3902 Refactor DLSCH/ULSCH scheduler: extract proportional fair policy behind function pointer interface
* !4136 hotfix for correct GFNI detection
* !4112 NAS UE Service Request fixes and improvements for Paging
* !4128 Iterate all NZP-CSI-RS resources per ResourceSet in scheduler
* !4131 Fix 8 DL ports
* !4137 changes in cudaMemadvise/cudaPrefetch API for v13
* !4122 Add Fedora 44/Ubuntu 26 to list of supported distributions
* !4117 NR_MAC/PHY: align SRS time_start_position semantics between L2 and L1
* !4129 CI: Clone from internal git repo
* !4124 Preparatory changes for LDPC CUDA integration