Fix/network browse seller 596

[twfhyr]

What

Adds explicit on-chain seller distinction to antseed network browse and antseed network peer CLI commands. When a peer operates as a delegated/proxy seller (i.e. metadata.sellerContract differs from peerId), the actual on-chain seller address is now surfaced separately from the peer/operator identity.

Changes

antseed network browse

• New "On-chain seller" column appears when any displayed peer has a sellerContract that differs from its peerId
• Non-delegated peers show — in the column; column is hidden entirely when no delegated sellers are present
• Footer note explains the distinction when the column is shown
• Both compact and expanded (--services) tables include the column
• JSON output (--json) adds sellerAddress and isDelegatedSeller per peer

antseed network peer <id>

• New "On-chain seller" line in the Peer section:
  • Delegated: shows seller contract address with attribution note — "delegated/proxy seller — channel stats and payments are attributed to the seller address"
  • Non-delegated: shows "same as peer"
• JSON output adds top-level sellerAddress and isDelegatedSeller fields

All pin/connect semantics (--peer, x-antseed-pin-peer) remain tied to peer.peerId — unchanged.

Why

Issue #596 — antseed network browse previously displayed peer.peerId as the visible seller identity. For delegated/proxy sellers (e.g. Venice-style setups), peerId is the operator EOA/node identity, while the actual on-chain seller is carried in peer.metadata.sellerContract. This made delegated sellers look visually wrong: the browse table showed the operator wallet as the seller, even though channel accounting and payments correctly used the seller contract address. The CLI presentation hid that distinction, making delegated/proxy sellers appear misconfigured.

Testing

• pnpm --filter @antseed/cli run typecheck passes
• pnpm --filter @antseed/cli run build passes
• Manual testing against live buyer daemon (49 peers):

Test	Result
network browse — no delegated sellers in top 5	Column hidden, table compact
network browse — Venice.ai Proxy in results	"On-chain seller" column shown, Venice row shows 1f228613…dedf18c9, others show —
network browse --services	Seller column present in expanded table
network browse --json	sellerAddress and isDelegatedSeller present on all peers; Venice has isDelegatedSeller: true
network peer <venice-id>	Shows "On-chain seller: 1f228613…" with attribution note
network peer <non-delegated-id>	Shows "On-chain seller: same as peer"
network peer <id> --json	sellerAddress and isDelegatedSeller at top level
Pin/connect hints	Still reference peer.peerId, unchanged

No new unit tests added — the network commands currently have no unit test coverage (pre-existing).

Checklist

• pnpm run build passes (@antseed/cli typecheck + build verified; full repo build fails on pre-existing native module issue unrelated to this change)
• pnpm run test passes (CLI has no test suite; other packages pass)
• Breaking changes documented — no breaking changes