feat(ETH): On-Chain + Off-Chain Hybrid Discovery

[SuchitraSwain]

What was wrong?

Issue #881

How was it fixed?

Summary of approach: Implemented a hybrid architecture that combines Ethereum smart contracts with py-libp2p's Kademlia DHT to achieve the best of both worlds.

Architecture Components:

1. Smart Contract Layer (ethereum_contract.py):

• Stores lightweight service pointers (service ID, DHT key, peer ID, owner)
• Provides trust and verifiability through blockchain
• Minimal gas costs (~200,000 gas vs 500,000+ for full metadata)

2. DHT Layer (hybrid_discovery_service.py):

• Stores detailed service metadata (endpoints, capabilities, real-time status)
• Enables frequent updates without gas costs
• Provides O(log n) lookup performance
• Supports real-time service discovery

3. Hybrid Resolver (hybrid_resolver.py):

• Combines on-chain verification with off-chain data retrieval
• Implements intelligent caching to reduce redundant lookups
• Provides health monitoring and service connection management
• Handles service discovery by type and individual service resolution

4. Mock Implementation (mock_ethereum.py):

• Allows testing and demonstration without real Ethereum setup
• Simulates gas cost savings and transaction behavior
• Enables standalone operation for development

To-Do

• Clean up commit history
• Add or update documentation related to these changes
• Add entry to the release notes

Cute Animal Picture

[sumanjeet0012]

@SuchitraSwain Please rebase the PR on latest main branch.