fix(mcp-server): resolve NFT owners and cover EVM resources (PLT-347) - #335

Solid, well-scoped fix: the NFT detail resource previously read a {address} param its URI template never defines, so owner was always "Unknown" — routing both the resource and the get_nft_info tool through a shared getERC721Owner corrects that, and the added tests (all 19 EVM resource handlers, plus a registration/URI-template guard) are a real coverage win. No blockers; remaining notes are about the half-applied "distinguish failure from absence" contract on isNFTOwner, raw provider error text now reaching the model, and minor docs/duplication cleanups.