Make IntelliJ LSP Client compilable against 2025.3

[alexander-doroshko]

@helin24

This PR makes the code in the third_party/thirdPartySrc/platform-lsp folder compilable against Android Studio Panda and IntelliJ IDEA 2025.3. The code stays compilable against 2026.1 and 2026.2.

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• I’ve reviewed the contributor guide and applied the relevant portions to this PR.

[gemini-code-assist]

Code Review

This pull request migrates blocking read actions to non-blocking alternatives across several LSP implementation files and configures the Dart language for the import optimizer. Feedback focuses on avoiding commented-out code or modifiers and addressing a bypassed canFormat check in LspImportOptimizer by using it.canFormat(psiFile) instead.

[alexander-doroshko]

This pull request migrates blocking read actions to non-blocking alternatives across several LSP implementation files

No, it doesn't :). I simply replaced new API calls to deprecated API calls that are 100% equivalent. This deprecated API is not going to be deleted any time soon, so it's safe to use it

[helin24]

This LGTM. My only outstanding questions are:

• These changes aren't going into intellij-community, right? Since that is available for 2026.2?
• Can we add these patches to the existing skill so we can reapply if we need to copy over these files again?

[alexander-doroshko]

This LGTM. My only outstanding questions are:

These changes aren't going into intellij-community, right? Since that is available for 2026.2?
Can we add these patches to the existing skill so we can reapply if we need to copy over these files again?

Discussed by email