fix: no mutation for caller owned payloads

[ferhatelmas]

What kind of change does this PR introduce?

Bug fix

What is the current behavior?

Event payloads are mutated to add version but they are owned by their callers.

What is the new behavior?

Do a shallow copy to add version to prevent nasty bugs.

Additional context

Related to any type changes (#922), extracted due to behavior changes.

[Copilot]

Pull request overview

This PR prevents mutation of caller-owned event payload objects when adding $version, reducing surprising side effects for event callers across sync/async queue paths.

Changes:

• Introduces a withPayloadVersion() helper to add $version via a shallow copy instead of mutating inputs.
• Updates Event.send, Event.invoke, Event.invokeOrSend, and Event.batchSend to use the copied payload.
• Adds Jest coverage ensuring payload objects passed into these APIs are not mutated.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/internal/queue/event.ts	Avoids mutating caller payloads by generating a shallow-copied payload with $version for static send/invoke APIs and batch inserts.
src/test/event.test.ts	Adds regression tests asserting caller payloads are not mutated and that queued batch payloads still include $version.

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[coveralls]

Coverage Report for CI Build 24196948700

Coverage increased (+0.02%) to 80.846%

Details

• Coverage increased (+0.02%) from the base build.
• Patch coverage: 21 of 21 lines across 1 file are fully covered (100%).
• No coverage regressions found.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

No coverage regressions found.

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Coverage Stats

Relevant Lines:	37225
Covered Lines:	30271
Line Coverage:	81.32%
Relevant Branches:	4139
Covered Branches:	3170
Branch Coverage:	76.59%
Branches in Coverage %:	Yes
Coverage Strength:	320.18 hits per line

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💛 - Coveralls