feat: Add plugin-nft-generation: create Solana NFT collections.

[xwxtwd]

Add plugin-nft-generation: support for creating Solana NFT collections.

Relates to:

N/A

Risks

Low - This plugin addition is isolated and doesn't affect existing functionality.

Background

What does this PR do?

The plugin supports creating Solana NFT collections through API integration and client interaction

What kind of change is this?

Features (non-breaking change which adds functionality)

Documentation changes needed?

Not required (environment variables are commented in .env.example)

Testing

Where should a reviewer start?

1. Review the plugin installation process
2. Check the NFT generation functionality
3. Verify API integration implementation

Detailed testing steps

1. Configure the following environment variables:

# Solana
SOLANA_PRIVATE_KEY=
SOLANA_PUBLIC_KEY=
SOLANA_ADMIN_PRIVATE_KEY= # This wallet is used to verify NFTs
SOLANA_ADMIN_PUBLIC_KEY= # This wallet is used to verify NFTs
SOLANA_VERIFY_TOKEN= # Authentication token for calling the verification API

2. Start the agent using any client (direct, Twitter, Telegram, etc.)
3. Tell the agent the instructions for creating a collection

[blockiosaurus]

Would it make sense to target the newer Core standard so minting costs are lower? Happy to help with that if you think it makes sense.

[xwxtwd]

Would it make sense to target the newer Core standard so minting costs are lower? Happy to help with that if you think it makes sense.

Yes, that makes sense. Thanks for offering to help!

[odilitime]

not sure I like it having it's own webserver, seems to duplicate a lot of what direct-client offers in that regard but since direct-client isn't extensible yet, we'll allow it for now. But will likely need to be change this in the future. And convert these into actions agents can take.

[xwxtwd]

1 failing check because the secrets.OPENAI_API_KEY configuration is missing.

#1027