fix: read full response body instead of truncating at 32KB

The challenge detection only needs a sample (32KB), but when the body
is not a challenge, the full body must be returned. The previous code
discarded everything after 32KB, causing Madara parsers to find 0
manga items in truncated HTML.

internal/httpclient/client.go

@@ -123,23 +123,31 @@ func (c *Client) Do(req *http.Request) (*http.Response, error) {
 		// Some Cloudflare challenge pages return HTTP 200 but contain challenge
 		// JavaScript. Check for challenge content on any response.
 		if resp.StatusCode == http.StatusOK {
-			body, readErr := io.ReadAll(io.LimitReader(resp.Body, 32*1024))
-			resp.Body.Close()
-			if readErr == nil && len(body) > 0 {
-				if isCloudflareChallenge(body) {
-					directStatus = http.StatusForbidden
-				} else {
-					// Not a challenge — wrap body and return
+			// Read a sample to check for challenge content
+			sample, readErr := io.ReadAll(io.LimitReader(resp.Body, 32*1024))
+			if readErr == nil && len(sample) > 0 && isCloudflareChallenge(sample) {
+				resp.Body.Close()
+				directStatus = http.StatusForbidden
+			} else {
+				// Read the rest of the body
+				rest, restErr := io.ReadAll(resp.Body)
+				resp.Body.Close()
+				if restErr == nil {
+					fullBody := append(sample, rest...)
 					return &http.Response{
 						StatusCode:    resp.StatusCode,
 						Header:        resp.Header,
-						Body:          io.NopCloser(bytes.NewReader(body)),
-						ContentLength: int64(len(body)),
+						Body:          io.NopCloser(bytes.NewReader(fullBody)),
+						ContentLength: int64(len(fullBody)),
 						Request:       req,
 					}, nil
 				}
-			} else {
-				return resp, nil
+				return &http.Response{
+					StatusCode: resp.StatusCode,
+					Header:     resp.Header,
+					Body:       io.NopCloser(bytes.NewReader(sample)),
+					Request:    req,
+				}, nil
 			}
 		} else if resp.StatusCode != http.StatusForbidden && resp.StatusCode != http.StatusServiceUnavailable {
 			return resp, nil