net: add blocking HTTP/HTTPS GET client

A small libssl-backed client (naut_http_get) that fetches a URL over
plain HTTP or TLS, follows 3xx redirects, and decodes Content-Length
and chunked bodies. Foundation for the RSS poller and Torznab search.
Built as a PIC static lib so it can link into the webui plugin module.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

include/naut/http_client.h

@@ -0,0 +1,26 @@
+/* http_client.h — minimal blocking HTTP/HTTPS GET client.
+ *
+ * Used by the web UI for RSS feed polling and Torznab indexer search. Supports
+ * plain HTTP and TLS (via OpenSSL), follows redirects, and returns the decoded
+ * response body. Intended for occasional fetches off the hot path. */
+#ifndef NAUT_HTTP_CLIENT_H
+#define NAUT_HTTP_CLIENT_H
+
+#include <stddef.h>
+#include "naut/common.h"
+
+typedef struct {
+    long   status;     /* HTTP status code (e.g. 200) */
+    char  *body;       /* malloc'd, NUL-terminated response body */
+    size_t body_len;   /* length of body, excluding the NUL */
+} naut_http_response;
+
+/* GET `url` (http:// or https://), following up to a handful of redirects.
+ * On NAUT_OK, `out` owns `out->body` (free with naut_http_response_free).
+ * Returns NAUT_ERR_* on transport/protocol failure. A non-2xx HTTP status is
+ * still returned as NAUT_OK with out->status set, so callers can inspect it. */
+naut_err naut_http_get(const char *url, naut_http_response *out);
+
+void naut_http_response_free(naut_http_response *r);
+
+#endif /* NAUT_HTTP_CLIENT_H */