Add Gemini Vertex AI integration with thinking budget support

[NewcomerAI]

• Add GeminiVertexLanguageModel class for Vertex AI authentication
• Extend extract() function with project, location, thinking_budget parameters
• Maintain full backward compatibility with existing API key approach
• Add comprehensive test suite and example code
• Include detailed documentation and migration guide

Features:

• Vertex AI authentication using project + location instead of API keys
• Thinking budget control for configurable reasoning capabilities
• Full feature parity with existing GeminiLanguageModel
• Schema constraints support for structured outputs
• Parallel processing and safety settings support
• Comprehensive error handling and validation

Files changed:

• langextract/inference.py: New GeminiVertexLanguageModel class
• langextract/init.py: Extended extract() function with new parameters
• examples/vertex_ai_example.py: Complete usage examples
• test_vertex_integration.py: Integration test suite
• VERTEX_AI_INTEGRATION.md: Comprehensive documentation

[github-actions]

Manual validation results:

Size: 825 lines
Template: ✗
Linked issue: ✗

Run ID: 16790802536

[github-actions]

Manual validation results:

Size: 825 lines
Template: ✗
Linked issue: ✗

Run ID: 16790874427

[github-actions]

Manual validation results:

Size: 825 lines
Template: ✗
Linked issue: ✗

Run ID: 16791195286

[github-actions]

Manual Validation Results

Status: ❌ Failed

Check	Status	Details
PR Size	✅	825 lines
Template	❌	Missing required sections
Linked Issue	❌	Missing Fixes/Closes #XXX

Errors:

• ❌ Missing PR template sections: # Description, Fixes #, # How Has This Been Tested?, # Checklist
• ❌ No linked issue found

View workflow run

[github-actions]

⚠️ Branch Update Required

Your branch is 9 commits behind main. Please update your branch to ensure CI checks run with the latest code:

git fetch origin main
git merge origin/main
git push

Note: Enable "Allow edits by maintainers" to allow automatic updates.

[github-actions]

⚠️ Branch Update Required

Your branch is 36 commits behind main. Please update your branch to ensure CI checks run with the latest code:

git fetch origin main
git merge origin/main
git push

Note: Enable "Allow edits by maintainers" to allow automatic updates.

[github-actions]

⚠️ Branch Update Required

Your branch is 86 commits behind main. Please update your branch to ensure CI checks run with the latest code:

git fetch origin main
git merge origin/main
git push

Note: Enable "Allow edits by maintainers" to allow automatic updates.

[github-actions]

⚠️ Branch Update Required

Your branch is 98 commits behind main. Please update your branch to ensure CI checks run with the latest code:

git fetch origin main
git merge origin/main
git push

Note: Enable "Allow edits by maintainers" to allow automatic updates.

[github-actions]

⚠️ Branch Update Required

Your branch is 106 commits behind main. Please update your branch to ensure CI checks run with the latest code:

git fetch origin main
git merge origin/main
git push

Note: Enable "Allow edits by maintainers" to allow automatic updates.

[github-actions]

⚠️ Branch Update Required

Your branch is 107 commits behind main. Please update your branch to ensure CI checks run with the latest code:

git fetch origin main
git merge origin/main
git push

Note: Enable "Allow edits by maintainers" to allow automatic updates.

[github-actions]

⚠️ Branch Update Required

Your branch is 109 commits behind main. Please update your branch to ensure CI checks run with the latest code:

git fetch origin main
git merge origin/main
git push

Note: Enable "Allow edits by maintainers" to allow automatic updates.

[github-actions]

⚠️ Branch Update Required

Your branch is 110 commits behind main. Please update your branch to ensure CI checks run with the latest code:

git fetch origin main
git merge origin/main
git push

Note: Enable "Allow edits by maintainers" to allow automatic updates.

[github-actions]

⚠️ Branch Update Required

Your branch is 111 commits behind main. Please update your branch to ensure CI checks run with the latest code:

git fetch origin main
git merge origin/main
git push

Note: Enable "Allow edits by maintainers" to allow automatic updates.