Replace every httptest.NewRequest call with
httptest.NewRequestWithContext using the test's t.Context(). Thread
t *testing.T through the createSetupFormRequest and
createLoginFormRequest helpers so they can supply a context.
make lint under golangci-lint 2.12.2 drops from 94 findings to 47
(remaining: 23 gosec, 24 goconst, tracked in #176/#177/#178). make
test and make fmt-check pass unchanged.
Closes#175
- Store lastSeen timestamp per IP limiter entry
- Lazy sweep removes entries older than 10 minutes on each request
- Add Retry-After header to 429 responses
- Add test for stale entry eviction
Fixes memory leak under sustained attack from many IPs.
