fix(test): properly verify deferred header flushing for non-WebSocket responses

[Copilot]

TestNonWebSocketResponseDoesNotFlushImmediately was asserting rec.Code == 200, but httptest.ResponseRecorder.Code defaults to 200 regardless of whether WriteHeader was ever called — making the assertion vacuously true.

Changes

• New writeHeaderTracker helper: wraps httptest.ResponseRecorder and sets a writeHeaderCalled bool when WriteHeader is actually invoked on the underlying writer
• Updated test assertion: replaced require.Equal(t, http.StatusOK, rec.Code) with require.False(t, rec.writeHeaderCalled) — directly verifying the interceptor defers the header flush

type writeHeaderTracker struct {
    *httptest.ResponseRecorder
    writeHeaderCalled bool
}

func (w *writeHeaderTracker) WriteHeader(code int) {
    w.writeHeaderCalled = true
    w.ResponseRecorder.WriteHeader(code)
}

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[fzipi]

@copilot fix the lint step in https://github.com/corazawaf/coraza-caddy/actions/runs/23027297918/job/66956554479?pr=272

[Copilot]

@copilot fix the lint step in https://github.com/corazawaf/coraza-caddy/actions/runs/23027297918/job/66956554479?pr=272

Fixed in c926a7e. The two errcheck lint failures were in TestRegularRequestStillProcessesResponseBody — added error checking for tx.ProcessRequestBody() and wrapped.Write(...).