Initial commit: akai-fetch - AKAI sampler ISO downloader & extractor

- fetch: Go CLI tool for searching, downloading, and extracting
  AKAI sampler ISOs from archive.org
- scripts/extract_wavs.sh: Shell script driving akaiutil to
  convert samples to WAV
- Dockerfile: Multi-stage build packaging akaiutil + fetch
- third_party/akaiutil: Vendored akaiutil v4.6.7 source (GPLv2)
- docs/akaiutil.md: Full akaiutil reference

Makefile

@@ -0,0 +1,21 @@
+BIN := fetch
+IMAGE := akai-fetch
+REMOTE := dhg.lol
+
+build:
+	CGO_ENABLED=0 go build -o $(BIN) .
+
+docker:
+	docker build -t $(IMAGE) .
+
+docker-run:
+	docker run --rm -v "$(PWD)/output:/data" $(IMAGE) $(ARGS)
+
+install: build
+	scp $(BIN) $(REMOTE):/tmp/$(BIN) && \
+	ssh $(REMOTE) "sudo mv /tmp/$(BIN) /DATA/Downloads/akai/$(BIN) && sudo chmod +x /DATA/Downloads/akai/$(BIN)"
+
+clean:
+	rm -f $(BIN)
+
+.PHONY: build docker docker-run install clean