feat(align): SMF parser, role guess, reference manifest

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/align/cli.ts

@@ -0,0 +1,33 @@
+import { parseArgs } from "node:util";
+import { addSong, trackKeys } from "../ref/manifest.ts";
+import { parseSmf } from "./smf.ts";
+
+const USAGE = `usage: bun run align add <audio> <midi> --id <id> [--title <t>] [--capo "<track name>=9"]...`;
+
+async function add(argv: string[]) {
+  const { values, positionals } = parseArgs({ args: argv, allowPositionals: true, options: { id: { type: "string" }, title: { type: "string" }, capo: { type: "string", multiple: true } } });
+  const [audio, midi] = positionals;
+  if (!audio || !midi || !values.id) throw new Error(USAGE);
+  const smf = parseSmf(new Uint8Array(await Bun.file(midi).arrayBuffer()));
+  const keys = new Set(trackKeys(smf.tracks));
+  const capo: Record<string, number> = {};
+  for (const c of values.capo ?? []) {
+    const i = c.lastIndexOf("=");
+    const k = c.slice(0, i), n = Number(c.slice(i + 1));
+    if (i < 0 || !Number.isInteger(n) || n < 0) throw new Error(`bad --capo ${JSON.stringify(c)}; expected "<track name>=<fret>"`);
+    if (!keys.has(k)) throw new Error(`--capo: no track named ${JSON.stringify(k)}; tracks: ${[...keys].map((x) => JSON.stringify(x)).join(", ")}`);
+    capo[k] = n;
+  }
+  const e = await addSong({ id: values.id, title: values.title ?? values.id, audio, midi, capo });
+  console.log(`added ${e.id} (${e.title})`);
+  for (const [k, r] of Object.entries(e.roles)) console.log(`  ${JSON.stringify(k)} -> ${r ?? "unmapped"}`);
+}
+
+const [cmd, ...rest] = process.argv.slice(2);
+try {
+  if (cmd === "add") await add(rest);
+  else throw new Error(USAGE);
+} catch (err) {
+  console.error((err as Error).message);
+  process.exit(1);
+}