salvage: hook delete path through nwsalvage

include/nwsalvage.h

@@ -3,6 +3,7 @@
 
 #include <stddef.h>
 #include <sys/types.h>
+#include <sys/stat.h>
 
 typedef int (*nwsalvage_ini_getter)(int entry, char *str,
                                      size_t strsize, void *data);
@@ -145,5 +146,14 @@ int nwsalvage_write_metadata(const char *metadata_path,
                              const struct nwsalvage_deleted_entry *entry);
 int nwsalvage_read_metadata(const char *metadata_path,
                             struct nwsalvage_metadata_entry *entry);
+/*
+ * Capture a server-side delete before nw_unlink_node() would remove it.
+ * Returns 0 when the file was moved to the recycle repository and metadata
+ * was written.  Returns 1 when salvage is disabled or the node is not
+ * salvageable and the caller should continue with the normal unlink path.
+ * Returns -1 on a real salvage failure; the caller should keep the live file.
+ */
+int nwsalvage_capture_node_delete(int volume, const char *unixname,
+                                  const struct stat *stb);
 
 #endif