Move Switch OTA launcher sources under ports/switch.

Consolidate the native OTA launcher, bootstrap, and assets into the Switch port tree.

ports/switch/ota-launcher/include/ota_unzip.h

@@ -0,0 +1,20 @@
+#ifndef GEN1_OTA_UNZIP_H
+#define GEN1_OTA_UNZIP_H
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Extract member_name from zip_path into dest_path.
+ * Tries exact member_name, then common prefixes (switch/gen1recomp/).
+ * Returns 0 on success. */
+int ota_unzip_extract_file(const char *zip_path, const char *member_name, const char *dest_path,
+                           char *err, size_t err_len);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif