refactor(agent): Migrate all tools to new class pattern

[TriveniSampleDatasets]

Summary

This pull request completes the migration of all function-based tools to the new class-based "Tool" abstraction. It introduces "CreateIssueTool" and "CreatePRTool" and guts the old github_tools.py file to only contain the necessary data models.

Closes #83

Type of Change

• feat - A new feature
• fix - A bug fix
• docs - Documentation only changes
• style - Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc)
• [**] refactor - A code change that neither fixes a bug nor adds a feature
• perf - A code change that improves performance
• test - Adding missing tests or correcting existing tests
• build - Changes that affect the build system or external dependencies (example scopes: gulp, broccoli, npm)
• ci - Changes to our Cl configuration files and scripts (example scopes: Travis, Circle, BrowserStack, SauceLabs)
• chore - Other changes that don't modify sc or test files
• revert - Reverts a previous commit
• security - A security fix or improvement
• github - Changes to our GitHub configuration files and scripts
• other (please describe):

Details

The old "github_tools.py" file mixed multiple responsibilities . This refactor separates these concerns by moving the tool logic into dedicated classes inside the tools/ directory, following the new Tool abstraction. The old github_tools.py file has been gutted to only contain the Pydantic data models, which are still imported by the new tool classes.

Screenshots / Recordings (if applicable)

Checklist

• I have read the CONTRIBUTING.md
• I have added/updated tests where applicable
• [] I have added screenshots or recordings for UI changes (if applicable)
• I have updated documentation where necessary