Nits: align SSE hook filename, tighten provider comment, correct client.tsx claim
Three unrelated cleanups from the review's nit pile.
use-sse-consumer.ts exported useStartSseConsumer but kept its pre-rename
filename, so the import path still read .../use-sse-consumer while the
symbol read useStartSseConsumer. Rename the file to match.
provider.tsx carried a ~10-line explanation of why it doesn't delegate
to useStartSseConsumer. The reasoning is sound, but the explanation was
longer than the code it described. Trim to the essentials.
client.tsx claimed the unauthenticated routes "don't need a WASM
context" — which is wrong. /devices/login loads WASM for seed-phrase
derivation, key generation, and OAuth. What those routes actually
skip is the OpakeProvider (FileManagerCache + SSE). Fix the comment
to say so.