Repair the test suite, fix eight engine defects, and add field-name mapping (0.1.0)
The test suite had never executed: vitest 4 transpiles with oxc, which does not
read experimentalDecorators from a tsconfig excluding the files it transforms,
so every decorator suite failed to parse and was reported as "0 test". Fixing
that revived 40 tests and exposed eight engine defects, each now pinned by a
regression test: inheritance silently discarding base-class constraints, a
circular reference exhausting the heap, stateful /g regexes in @Matches, an
unmatched polymorphic discriminator dropping data, serializers crashing on unset
optional properties, null-prototype objects, __proto__ from untrusted JSON, and
mangled or overwritten error messages.
Adds field-name mapping (@JsonProperty, @JsonAlias, naming strategies), access
control (@JsonIgnore, @JsonReadOnly, @JsonWriteOnly), transform options,
error-flattening helpers, and 30 validation decorators.
40 tests that never ran -> 136 that do, at 97% statement and 100% function
coverage, green on Node 20, 22 and 24.