[P2] Clean up Windows UUID format warnings (C4477)

[currentsuspect]

Goal

Reduce Windows build warning noise in UUID formatting and harden cross-platform formatting.

Scope

• Fix %016lx formatting warnings for uint64_t in AestraUUID paths.
• Use portable format strategy (<inttypes.h> macros or equivalent).
• Validate with Windows compiler in CI.

Acceptance Criteria

• C4477 warnings for UUID formatting removed.
• No behavior change in UUID output format.