fix: restore last selected model state (#1021)

[mihaibuba]

Pull Request

Description

Fixing regression: Last selected AI model is reset on new conversation.

Type of Change

• Bug fix (non-breaking change which fixes an issue)

Related Issue

Fixes #1021

Changes Made

Added global variables which remember the last provider and model;
Moved the default provider and model to a default constant
Falls back to the default values from the constant

Testing

How has this been tested?

• Manual testing in IntelliJ IDEA
• Tested with cloud LLM (Gemini)

Test Configuration:

• IntelliJ IDEA version: 2026.1
• JDK version: 25.0.2
• OS: Ubuntu 24.04.4 LTS

Documentation

Checklist

• My code follows the existing code style
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published

Screenshots/Videos (if applicable)

Additional Notes

I could only test this on Intellij version 2026.1; because of the following caveats:

• Debugging the plugin in this version required upgrading in build.gradle.kts the following dependencies:

    kotlin("jvm") version "2.3.21"
    kotlin("plugin.lombok") version "2.3.21"
    kotlin("plugin.compose") version "2.3.21"
    id("org.jetbrains.intellij.platform") version "2.15.0"

adding the repository:

jetbrainsRuntime()

and updating the following line:
create("IC", providers.gradleProperty("ideVersion").orElse("2025.1.7")) {}
to:
intellijIdea(providers.gradleProperty("ideVersion").orElse("2026.1"))

Upgrading the package versions to 2.3.0 and above causes the plugin on Intellij version 2025.3.3 to no longer start.

Breaking Changes

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By submitting this pull request, I confirm that my contribution is made under the terms of the project's license.