[v0.3.0] Multi-Backend Storage — Walrus, Storage Abstraction

[kdh4win4]

Summary

Expand permanent storage beyond Arweave to support emerging decentralized storage networks, starting with Walrus (SUI ecosystem).

Planned Features

• Walrus storage adapter — add Walrus as an alternative/complementary archival backend
• Storage abstraction layer — unified StorageBackend interface so users can plug in Arweave, Walrus, or future providers interchangeably
• Redundant archival mode — option to simultaneously archive to multiple backends for maximum durability

Design Notes

# Proposed interface sketch
class StorageBackend(ABC):
    @abstractmethod
    def upload(self, metadata: dict) -> str:  # returns TX ID
        ...
    @abstractmethod
    def fetch(self, tx_id: str) -> dict:
        ...

class ArweaveBackend(StorageBackend): ...
class WalrusBackend(StorageBackend): ...

Related

• Depends on: v0.1.0 Arweave uploader
• Complements: v0.2.0 on-chain verification (Walrus is SUI-native)
• See also: ROADMAP.md