MPSBoost 0.2.0rc0 Release Audit

0.2.0rc0 was the cache and stability release candidate before the formal 0.2.0 release.

Included:

• versioned L2 cache keys;
• atomic writes and checksum validation;
• damaged-cache invalidation;
• public cache diagnostics, explicit cache creation, and safe cache clearing;
• tighter CI cache boundaries.

Not included:

• all-tree model families;
• classification breadth;
• advanced objectives and explanations.