Optimize code size: mark more properties as mangled.

[dumganhar]

Re: #18222

Some @engineInternal properties could also be marked as @mangle.

Changelog

---

Continuous Integration

This pull request:

• needs automatic test cases check.

  Manual trigger with @cocos-robot run test cases afterward.

• does not change any runtime related code or build configuration

  If any reviewer thinks the CI checks are needed, please uncheck this option, then close and reopen the issue.

---

Compatibility Check

This pull request:

• changes public API, and have ensured backward compatibility with deprecated features.
• affects platform compatibility, e.g. system version, browser version, platform sdk version, platform toolchain, language version, hardware compatibility etc.
• affects file structure of the build package or build configuration which requires user project upgrade.
• introduces breaking changes, please list all changes, affected features and the scope of violation.

[github-actions]

👍 Package size ⤵ -4165 bytes, old: 5225108, new: 5220943

Interface Check Report

This pull request does not change any public interfaces !

[dumganhar]

@cocos-robot run test cases

[github-actions]

@dumganhar, Please check the result of run test cases:

• Test Platform: PR-Test
• Editor Version: v3.8.6
• Task Result: PASS
• Task URL: https://cctest.cocos.org/#/reportview/PR-TEST/d68c3eb0-d643-4f37-a909-f5fb092e6c6f/-1
• GitHub Action: https://github.com/cocos/cocos-engine/actions/runs/13152125665

Task Details

[github-actions]

@dumganhar, Please check the result of run test cases:

• Test Platform: PR-Test
• Editor Version: v3.8.6
• Task Result: FAIL
• Task URL: https://cctest.cocos.org/#/reportview/PR-TEST/5138cb7e-8641-4daf-966e-da1fa0065dbf/-1
• GitHub Action: https://github.com/cocos/cocos-engine/actions/runs/13152125665

Task Details

Platform	build	boot	runned	crashScene	FailScene
windows	PASS	PASS	PASS
android	PASS	PASS	PASS
wechatgame	PASS	FAIL	FAIL