Add workspace validation and GitHub PAT verification for Hive Chat

[aliraza556]

Problem

Previously, users could access Hive Chat without having a properly configured workspace. This led to failed requests, confusion, and poor user experience when attempting to use Hive Chat without the necessary setup:

• Code Graph URL
• Secret Alias
• CodeSpace URL
• GitHub username
• GitHub PAT (Personal Access Token)

Additionally, expired GitHub PATs were only detected after attempting to send a message, resulting in runtime errors.

Solution

This PR implements validation checks for workspace configuration and GitHub PAT validity before allowing users to send messages in Hive Chat.

Key Changes:

• Workspace Setup Validation: Check for all required workspace configuration fields
• GitHub PAT Verification: Validate PAT using GitHub API before message execution
• Enhanced User Feedback: Show informative splash screens for incomplete setup
• UI Improvements: Disable input field and buttons when setup is incomplete
• Navigation Help: Add direct links to settings page to complete workspace setup

User Experience Improvements

• Clear Guidance: Users immediately see why Hive Chat isn't working and how to fix it
• Proactive Validation: Issues are caught before attempting to send messages
• Reduced Errors: Prevents failed API requests due to missing configuration
• Streamlined Setup: Direct links to settings page make it easy to complete configuration

Technical Implementation

• Added getCodeSpaceConfig method to MainStore
• Added validation functions for workspace setup and GitHub PAT
• Enhanced ChatSplashScreen component to show conditional content
• Integrated axios for GitHub API requests
• Added state management for tracking validation status

Testing Instructions

1. Create a new workspace with incomplete configuration (missing code graph, alias, or PAT)
2. Access Hive Chat - verify you see the "Workspace Incomplete" screen
3. Try with expired/invalid GitHub PAT - verify the appropriate message is displayed
4. Complete all required configuration - verify you can use Hive Chat normally

Closed: #1545

Demo:

https://www.loom.com/share/bbda623f74b8424eaba2772e374d8e44

[aliraza556]

@tomsmith8 Please review this PR.

[kevkevinpal]

Looks good, I'm going to merge if you can fix the two comments I made in a followup PR