feat: combine save/apply

resolves #45

src/lib/backup/compat/legacy-chords.sample.csv

@@ -0,0 +1,26 @@
+e + b + a,babe
+e + c + b,because
+f + e + c + a,face
+h + e + c + a,each
+i + d + ',I'd
+i + g + b,big
+i + g + e,give
+k + b + a,back
+k + e + a,take
+l + e + a,late
+l + e + d + a,lead
+l + f + e,feel
+l + g + e + a,large
+l + h + e,help
+l + i + a,Lia
+l + i + f,fill
+l + i + f + e,life
+l + i + g + b + a,gitlab
+l + k + i + e,like
+m + e + a,make
+m + i + ',I'm
+n + c + a,can
+n + d + a,and
+n + e + b,been
+n + e + b + a,enable
+n + e + d,end

src/lib/backup/compat/legacy-chords.sample.json

@@ -0,0 +1,26 @@
+e + b + a,babe
+e + c + b,because
+f + e + c + a,face
+h + e + c + a,each
+i + d + ',I'd
+i + g + b,big
+i + g + e,give
+k + b + a,back
+k + e + a,take
+l + e + a,late
+l + e + d + a,lead
+l + f + e,feel
+l + g + e + a,large
+l + h + e,help
+l + i + a,Lia
+l + i + f,fill
+l + i + f + e,life
+l + i + g + b + a,gitlab
+l + k + i + e,like
+m + e + a,make
+m + i + ',I'm
+n + c + a,can
+n + d + a,and
+n + e + b,been
+n + e + b + a,enable
+n + e + d,end

src/lib/backup/compat/legacy-chords.ts

@@ -0,0 +1,21 @@
+import { KEYMAP_IDS } from "$lib/serial/keymap-codes"
+import type { CharaChordFile } from "$lib/share/chara-file"
+
+
+export function csvChordsToJson(csv: string): CharaChordFile {
+  return {
+    charaVersion: 1,
+    type: 'chords',
+    chords: csv.split('\n').map(line => {
+      const [input, output] = line.split(',', 2)
+      return [
+        input.split('+').map(it => KEYMAP_IDS.get(it.trim())?.code ?? 0),
+        output.split('').map(it => KEYMAP_IDS.get(it.trim())?.code ?? 0),
+      ]
+    })
+  }
+}
+
+export function isCsvLayout(csv: string): boolean {
+  return /^((\s*\w+\s*+?),\s*\w+\n?)+$/.test(csv)
+}