850c3ff8e9
- StdinSource reads from an injectable io.Reader (INPUT-03) - URLSource fetches http/https with 30s timeout, 50MB cap, scheme whitelist, and Content-Type filter (INPUT-04) - ClipboardSource wraps atotto/clipboard with graceful fallback for missing tooling (INPUT-05) - emitByteChunks local helper mirrors file.go windowing to stay independent of sibling wave-1 plans - Tests cover happy path, cancellation, redirects, oversize bodies, binary content types, scheme rejection, and clipboard error paths