Fix CI failures: PQ stub SKIP guards, MSVC max macro, fuzz CTR gracef… #52

Job	Run time
ASan + UBSan (Ubuntu)	2m 56s
Full Suite 394/394 (Ubuntu)	4m 31s
Post-Quantum PQ (Ubuntu)	3m 40s
Server Codecs (Ubuntu)	4m 22s
UBSan (Ubuntu)	2m 16s
Build & Test (Windows / MSVC)	4m 13s
TSan (Ubuntu)	2m 43s
Build & Test (ubuntu-24.04)	2m 58s
Coverage (Ubuntu, Clang-18)	2m 13s
Benchmarks (Ubuntu)	9m 41s
Mutation Testing Baseline (Ubuntu)	20s
Python SAST (bandit)	9s
Fuzz (Ubuntu, Clang-18)	30m 54s
License Compliance	1m 27s
Secrets Scan (gitleaks)	5s
Build & Test (macos-14)	1m 33s
	1h 14m 1s

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