fix(query): include preview of current and incoming update in error when merging normal update with pipeline

[vkarpov15]

Re: #15928

Summary

@AbdelrahmanHafez 's comments on #15928 were accurate, I had a lot of trouble diagnosing the error in #15928 when I first ran into it.

Examples

[Copilot]

Pull request overview

This PR improves error messages when mixing incompatible update types (array vs object) by including a preview of both the current and incoming updates. This enhancement makes it significantly easier to diagnose and fix issues related to mixing normal updates with pipeline updates.

Key changes:

• Enhanced error messages to display previews of conflicting updates
• Added _previewUpdate() helper function to format update objects for display

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
lib/query.js	Added _previewUpdate() helper function that uses util.inspect() to format update objects with appropriate constraints (depth, array length, total length), and updated three error messages to include current and incoming update previews
test/model.updateOne.test.js	Added test case to verify that error messages include properly formatted previews when mixing array and object updates

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