Pure performance scope

This candidate changes only TableRenderSnapshotFactory viewer-ID preprocessing and an exact behavior-preservation test. It does not include the closed #57 occupied-seat optimization and does not change game rules, visibility policy, packet behavior, timers, interactions, or supported platforms.

Candidate

Each distinct viewer UUID is serialized exactly once per create() call into a private (UUID id, String serializedId) record. The records are sorted by serializedId, preserving the existing Comparator.comparing(UUID::toString) order exactly. Membership signatures append the cached strings, while exclusion lists retain the original UUID objects and ordering.

The test covers:

• duplicate viewer UUID removal before serialization
• a high-bit UUID whose UUID.compareTo ordering differs from its serialized string ordering
• exact exclusion UUID order
• exact delimiter-free membership signature characters
• occupied-but-offline and empty-viewer behavior

Evidence policy

No performance claim is made from source inspection. GitHub Build/Test must pass before the trusted base-owned snapshot A/B gate is enabled. Only PASS_OPTIMIZED permits readying and expected-head squash merge; inconclusive or regressed evidence closes the candidate without merge.

No Gradle, JMH, test, or server workload was run locally.