Optimize git remote queries with session cache

[everpcpc]

Summary

This PR optimizes git remote information handling by caching repository metadata in the session instead of repeatedly executing git commands.

Changes:

• Cache git remote info (owner/repo, fork status, origin owner/repo, current branch) in session state
• Initialize git cache when session loads
• Refactor push/update prompts in MainLayout to use cached data instead of instructing repeated git remote -v and URL parsing
• Add IPC handler for sessions:init-git-cache

Benefits:

• Reduces redundant git command executions
• Improves performance for git operations
• Simplifies prompt instructions by removing repetitive git remote parsing logic

Tests

• No Test - Refactoring existing functionality, behavior unchanged

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 could cause existing functionality not to work as expected)
• Documentation Update
• Refactoring
• Performance Improvement
• Other (please describe):