Enhance installation experience with improved PATH handling

[shubham-pampattiwar]

Overview

This PR improves the user experience during installation by providing clearer guidance and better PATH management to help users get kubectl oadp working immediately after installation.

Background

Currently, users may experience confusion after running make install when kubectl oadp doesn't work immediately. This typically happens when ~/.local/bin isn't in their current terminal session's PATH, even if it's configured in their shell profile.

Improvements

1. Enhanced PATH Detection & Feedback

• Added clear status messages to show whether the install directory is in the current PATH
• Provides immediate feedback about PATH configuration status

2. Current Session Support

• Now provides the exact export PATH=... command for immediate use
• Users can start using kubectl oadp right away without restarting their terminal

3. Improved Shell Configuration Detection

• Enhanced pattern matching to only detect active (non-commented) PATH exports
• Uses regex ^[[:space:]]*export[[:space:]]*PATH.*\.local/bin for more accurate detection

4. Installation Verification

• Automatically verifies that kubectl oadp is accessible after installation
• Uses scoped PATH modification for testing without affecting the user's session
• Displays version information when cluster access is available

5. Clearer User Guidance

• Organized instructions into logical sections:
  • 🔧 Immediate solution for current session
  • 🔄 Setup for future sessions
  • 🧪 Verification results
  • 📋 Helpful next steps

6. Updated Documentation

• Refined README.md to better explain the installation process
• Improved language around PATH setup requirements

Example Output

The new installation experience provides clear, actionable guidance:

✅ Installed to ~/.local/bin
🔍 Checking PATH configuration...
⚠️  ~/.local/bin is not in your current PATH

🔧 To use kubectl oadp in this terminal session:
   export PATH="~/.local/bin:$PATH"

🔄 For future sessions:
   Restart your terminal or run: source ~/.zshrc

🧪 Verifying installation...
✅ Installation verified: kubectl oadp plugin is accessible

This change helps ensure users can successfully use the CLI immediately after installation while providing clear guidance for both immediate and future use.

🤖 Generated with Claude Code

[Joeavaikath]

lgtm!