feat: add PR review and autonomous comment resolution commands

[iamladi]

Summary

Adds two new commands to enhance GitHub PR workflows:

1. /review-pr - Comprehensive PR review with detailed analysis
2. /address-pr-comments - Interactive/autonomous PR comment resolution with AI confidence scoring

Changes

/review-pr Command

• Fetches PR metadata, diffs, and comments via gh CLI
• Checks out PR branch and compares against base
• Provides systematic file-by-file review
• Analyzes CI/CD status and discussion context
• Outputs structured recommendations with actionable feedback

/address-pr-comments Command

• Interactive mode: Present comments for user selection
• Autonomous mode: Auto-detect CI/CD environments and address high-confidence items
• AI confidence scoring (0-100) based on specificity, language clarity, category, reviewer authority
• Safety mechanisms: Git stash checkpoints, rollback instructions
• Detailed execution reports with skipped items analysis

Updated Files

• .claude-plugin/plugin.json - Registered both new commands
• commands/review-pr.md - PR review workflow
• commands/address-pr-comments.md - Comment resolution workflow
• README.md - Updated documentation
• CHANGELOG.md - Version 1.2.0 changes
• package.json - Version bump

Test Plan

• /review-pr <number> works with PR number
• /review-pr <url> works with full GitHub URL
• /address-pr-comments <number> runs in interactive mode
• /address-pr-comments <number> --autonomous runs autonomously
• Plugin validation passes
• Commands are properly registered in plugin config