Fix race condition in PersistentPlayerDataContainerView.snapshot()

[Copilot]

The snapshot() method released the read lock before deep-copying the tag, allowing concurrent writes to mutate FastCompoundBinaryTag during traversal—causing potential corruption or exceptions.

Changes

• Introduced snapshotTag() template method in PersistentPlayerDataContainerViewImpl that subclasses override to control locking scope
• Extended lock coverage in CommonCloudPlayerImpl.persistentDataView to hold read lock for entire snapshot operation (tag retrieval + deep copy)

Example

// Before: lock released between toTagCompound() and deepCopy()
override fun snapshot(): PersistentPlayerDataContainerViewImpl {
    val tag = deepCopy(toTagCompound())  // toTagCompound() acquires+releases lock
    // deepCopy() executes without lock protection ← race window
}

// After: entire operation under lock
override fun snapshotTag() = ppdcReentrantLock.read { 
    super.snapshotTag()  // both toTagCompound() and deepCopy() now protected
}

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[github-actions]

Qodana for JVM

It seems all right 👌

No new problems were found according to the checks applied

💡 Qodana analysis was run in the pull request mode: only the changed files were checked
☁️ View the detailed Qodana report

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