Drop node identity, add lexicon definitions and Tauri desktop app
Remove the did:web node identity layer — p2pds is now infrastructure
that acts on behalf of authenticated atproto users, not an entity with
its own identity. Records (peer, offer) publish to the user's own repo.
- Delete src/node-identity.ts and its tests
- Remove NODE_DID, NODE_MANAGERS, NODE_NAME from Config
- Simplify server.ts (single repo), index.ts (no NodeIdentityOpts),
auth.ts (config.DID only), replication-manager.ts (no peer publishing)
- Update all xrpc handlers and 13 test files
- Add lexicon JSON schemas for org.p2pds.peer and org.p2pds.replication.offer
- Add src/lexicons.ts loader/validator, wire into RecordValidator
- Add Tauri v2 desktop app skeleton at apps/desktop/ with sidecar pattern
- Add npm workspaces config