feat: layout url import

feat: backup import (except chords)
feat: legacy layout import
feat: separate layout, chord & setting backup downloads

src/lib/backup/compat/legacy-layout.spec.ts

@@ -0,0 +1,18 @@
+import {describe, expect, it} from "vitest"
+import legacyLayout from "./legacy-layout.sample.csv?raw"
+import legacyLayoutConverted from "./legacy-layout-converted.sample.json"
+import {csvLayoutToJson, isCsvLayout} from "./legacy-layout"
+
+describe("legacy layout", () => {
+  it("should detect a legacy layout", () => {
+    expect(isCsvLayout(legacyLayout)).to.be.true
+  })
+
+  it("should not detect chord maps as layouts", () => {
+    expect(isCsvLayout("e + h + t,the")).to.be.false
+  })
+
+  it("should convert legacy layouts", () => {
+    expect(csvLayoutToJson(legacyLayout)).to.deep.equal(legacyLayoutConverted)
+  })
+})