Edit XCHandles NFT metadata atomically

Parent: #867
Depends on: unified XCHandles profile modeling under #867.

Summary

Support full, atomic metadata replacement for XCHandles NFTs instead of Sage's existing append-only NFT URI update path.

Scope

• Use AnyMetadataUpdater / Nft::transfer_with_metadata and HandleNftMetadata for compatible handle NFTs.
• Add typed request/response models and validated UI fields for display name, avatar/image, resolved address/profile fields, URIs, and hashes supported by the protocol.
• Preview the exact old/new metadata and resulting launcher/owner relationships before signing.
• Verify the confirmed NFT metadata and live registry mapping after submission, refresh caches, and surface mismatch/change warnings.
• Keep ordinary NFT URI updates unchanged.

Acceptance criteria

• A compatible owned handle NFT can atomically replace all supported metadata fields.
• Invalid metadata, hashes, URIs, unsupported updater puzzles, and non-owned NFTs are rejected before signing.
• Confirmation clearly distinguishes local display data from on-chain metadata.
• Post-confirmation verification detects unexpected metadata or registry changes.
• Simulator tests cover blank-to-populated and populated-to-updated handle metadata without changing launcher identity.

Start with parent issue #867 and the unified XCHandles profile modeling it describes, then trace the existing Sage NFT URI update path. Read the AnyMetadataUpdater, Nft::transfer_with_metadata, and HandleNftMetadata interfaces before defining the request, response, validation, preview, and verification boundaries. Done means the acceptance criteria pass, including simulator coverage for blank-to-populated and populated-to-updated metadata.