- Wrap all JsonDocument.Parse calls in using blocks and Clone() each
retained JsonElement to eliminate UAF hazard after GC.
- Use JsonSerializer.Serialize with UnsafeRelaxedJsonEscaping so event
names with " or \ produce \" / \ rather than " / plain \;
avoids malformed JSON on Encode().
- Guard the [ ] block in Encode() behind EventName-or-args check so
Connect/Disconnect packets round-trip as bare "0"/"1" not "0[]".
- Add three regression tests: Connect no-bracket, Event round-trip,
special-char event name escaping.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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