Integration 2026 week 14

* !4019 Change OAI license to CSSL v1.0
* !4021 hotfix for 4 layer mapping on aarch64
* !4022 UE: Fix CSI RS Measurement
* !4010 UE: Implement SUCI Profile Scheme A
* !4012 More compilation improvements
* !4027 CI: fix Aerial conf for test with 30 MHz BW
* !3948 Update doc: split RUNMODEM.md, clarify USRP-specific workarounds
* !4026 RRC/E1 bugfixes: handle missing UE context, don't send E1 msg if no PDU session
* !3996 Switch xran lib repo to https://github.com/openairinterface/o-du-phy.git
* !4020 Remove a lot of unused code and defines
* !3969 Acceleration of channel convolution
* !4023 Cleanup common_lib.h
* Clarifications on license
* !4017 CI: Add stage to push to local git repository