chore: bump version to v1.4.0 and use proper icons for provider settings

[stephanj]

• Bump version to 1.4.0 in build.gradle.kts, plugin.xml, and application.properties
• Add v1.4.0 changelog entries for Exo provider and related features
• Use download icon for local LLM providers (Ollama, LMStudio, GPT4All, Jan, LLaMA.c++)
• Use info icon for Exo provider (no API key, links to documentation)
• Fix LLaMA.c++ URL to point to https://github.com/ggml-org/llama.cpp

Pull Request

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Description

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Code refactoring
• Performance improvement
• Test addition/improvement

Related Issue

Fixes #
Closes #
Related to #

Changes Made

Testing

How has this been tested?

• Unit tests
• Integration tests
• Manual testing in IntelliJ IDEA
• Tested with local LLM (Ollama/LMStudio/GPT4All)
• Tested with cloud LLM (OpenAI/Anthropic/Gemini)
• Tested with MCP servers
• Tested with RAG enabled

Test Configuration:

• IntelliJ IDEA version:
• JDK version:
• OS:

Documentation

• I have updated the documentation at genie.devoxx.com if needed
• I have updated CLAUDE.md if architecture/patterns changed
• I have added/updated code comments for complex logic
• I have updated the README.md if needed

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

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Breaking Changes

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