[mcculls]

Reduce remaining gaps in test coverage with tests for large trie serialization and generation, insertion edge cases, repeated class-injection enablement, and object-store isolation. Testing the remaining coverage would require fragile or convoluted tests, as well as exposing internals.

Coverage across Java 8, 11, 17, 21 and 25:

Module	Line coverage	Branch coverage
Overall	98.46%	96.34%
class-match	100.00%	99.70%
class-inject	86.36%	86.36%
utils	99.17%	97.49%
field-inject	95.14%	73.44%