fix(documentarray): reindex subdocs after reordering

[AbdelrahmanHafez]

Document array operations that remove or reorder entries can leave surviving subdocs with stale __index values. After operations like pull(), shift(), splice(), $shift(), unshift(), positioned push(), sort(), or reverse(), a subdoc can still think it lives at its previous array index. A later nested change can then mark and save the wrong path, for example addresses.1.city instead of addresses.0.city.

This PR:

• restamps document-array subdoc indexes after operations that can move existing subdocs
• keeps append-only push() on the fast path, because the new subdoc is already cast with the correct appended index
• refreshes the parent populated cache after reorder operations that can change doc.populated('array.refPath') order, including sort() and reverse()
• makes document-array reverse() register a full-array $set, matching other reorder operations and avoiding stale pending atomics after a prior $push
• adds regression coverage for wrong nested modified paths, persistence after save, populated-cache order, and reverse atomics

[Copilot]

Pull request overview

This PR fixes document array subdocument index bookkeeping after removals so later nested mutations mark the correct path.

Changes:

• Reindexes surviving subdocuments after pull(), shift(), and splice().
• Preserves populated cache updates in the same wrappers.
• Adds regression coverage for saving after removal and mutating the first remaining subdocument.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
lib/types/documentArray/methods/index.js	Adds subdocument index restamping after selected document-array removal operations.
test/types.documentarray.test.js	Adds regression tests for pull(), splice(), and shift() reindex behavior.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

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

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

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