Mechanical split — client.rs (1027 lines) into client/ module directory. Three files: transport.rs (HTTP types + Transport trait), xrpc.rs (XrpcClient + auth), did.rs (DID resolution + unauthenticated cross-PDS). Glob re-exports in mod.rs preserve exact public API — zero consumer changes.
Mechanical split — client.rs (1027 lines) into client/ module directory. Three files: transport.rs (HTTP types + Transport trait), xrpc.rs (XrpcClient + auth), did.rs (DID resolution + unauthenticated cross-PDS). Glob re-exports in mod.rs preserve exact public API — zero consumer changes.