feat: Enhance M3U parser to normalize URLs based on server address

- Added a `normalizeUrl` function to replace protocol, hostname, and port in URLs with the current window location if they match the server address.
- Updated `parseM3U` function to accept an optional `serverAddress` parameter and normalize `tvgUrl`, `catchupSource`, and channel URLs accordingly.
- Modified `PlayerPage` to extract the server address from the `X-Server-Address` header and pass it to the `parseM3U` function.

Author: stackia

src/connection.c

@@ -967,12 +967,25 @@ static void handle_playlist_request(connection_t *c)
   }
 
   size_t playlist_len = strlen(playlist);
-  char extra_headers[128];
+  char *server_addr = get_server_address();
+  char extra_headers[256];
 
-  snprintf(extra_headers, sizeof(extra_headers),
-           "Content-Type: audio/x-mpegurl\r\n"
-           "Content-Length: %zu\r\n",
-           playlist_len);
+  if (server_addr)
+  {
+    snprintf(extra_headers, sizeof(extra_headers),
+             "Content-Type: audio/x-mpegurl\r\n"
+             "Content-Length: %zu\r\n"
+             "X-Server-Address: %s\r\n",
+             playlist_len, server_addr);
+    free(server_addr);
+  }
+  else
+  {
+    snprintf(extra_headers, sizeof(extra_headers),
+             "Content-Type: audio/x-mpegurl\r\n"
+             "Content-Length: %zu\r\n",
+             playlist_len);
+  }
 
   send_http_headers(c, STATUS_200, CONTENT_HTML, extra_headers);
   connection_queue_output_and_flush(c, (const uint8_t *)playlist, playlist_len);

src/m3u.c

@@ -254,7 +254,7 @@ static int is_private_ipv4(const char *ip_str)
  * Priority: hostname config > non-upstream interface private IP > non-upstream interface public IP > upstream interface IP > localhost
  * Returns: malloc'd string (caller must free)
  */
-static char *get_server_address(void)
+char *get_server_address(void)
 {
     struct ifaddrs *ifaddr, *ifa;
     char *result = NULL;

src/m3u.h

@@ -37,4 +37,10 @@ void m3u_reset_transformed_playlist(void);
  */
 void m3u_reset_external_playlist(void);
 
+/* Get server hostname or IP address with priority logic
+ * Priority: hostname config > non-upstream interface private IP > non-upstream interface public IP > upstream interface IP > localhost
+ * Returns: malloc'd string (caller must free)
+ */
+char *get_server_address(void);
+
 #endif /* __M3U_H__ */