sdls: add TODO for FSR interop via CryptoLib TM path
FSR (Frame Security Report) interop requires:
1. Crypto_Init_TM_Unit_Test() for SA setup
2. A full 1786-byte TM frame matching CryptoLib's config
3. Crypto_TM_ApplySecurity() to produce secured frame
4. Crypto_Get_FSR() to read the 32-bit FSR word
The TM frame must be copied from CryptoLib's own ut_tm_apply.c
HAPPY_PATH_CLEAR_FECF test (3572-char hex literal). Tracked
separately from the TC interop which is already working.