Security 8.19.10 release notes

[natasha-moore-elastic]

Resolves #7121: adds the 8.19.10 Security end Endpoint release notes.

Preview: 8.19.10

1. Did you use a generative AI (GenAI) tool to assist in creating this contribution?

• Yes
• No

Tool(s) and model(s) used:
Cursor, claude-4.5-opus-high

[github-actions]

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[e40pud]

LGTM

[gabriellandau]

Suggested change

	* Improves the {elastic-defend} startup log to explain details about unsigned policies.
	* Improves the {elastic-defend} startup log to explain details about unsigned policies.
	* Optimizes the {elastic-defend} kernel driver to collect file and registry access events more efficiently, improving overall system responsiveness and reducing CPU usage.

[gabriellandau]

Suggested change

	* Fixes an issue in {elastic-defend} on Windows where Mark of the Web parsing incorrectly handled file origin information ending with a `\\0`.
	* Fixes an issue in {elastic-defend} on Windows where Mark of the Web parsing incorrectly handled file origin information ending with a `\\0`.
	* Reduces the occurrence of Linux {elastic-defend} policy failures due Malware protections system deadlock avoidance.
	* Fixes an issue in {elastic-defend} that could result in delayed or missing malware-on-write alerts.
	* Fixes a bug in {elastic-defend} on Windows that can sometimes result in `KERNEL_AUTO_BOOST_LOCK_ACQUISITION_WITH_RAISED_IRQL` or `PAGE_FAULT_IN_NONPAGED_AREA` bugchecks when [Offloaded Data Transfer (ODX)](https://learn.microsoft.com/en-us/windows-hardware/drivers/storage/offloaded-data-transfer) is used to copy files. This regression was introduced in {elastic-defend} versions 8.19.8, 9.1.8, and 9.2.2.

[stephmilovic]

Suggested change

	* Fixes an issue where the Security AI Assistant API didn't use an associated conversation's system prompt ({kibana-pull}248020[#248020]).
	* Fixes an issue where the Security AI Assistant chat completion API didn't use an associated conversation's system prompt ({kibana-pull}248020[#248020]).

Sorry, missed this on my first pass. We should specify which API