fix: prevent database is locked on concurrent startup

Set busy_timeout before journal_mode=WAL in db.ts so SQLite retries
for 10s instead of failing immediately with the default 0ms timeout.

Extract migration into a dedicated Docker Compose service so both
jetstream and api wait for it to complete before opening the database.

src/data/db.ts

@@ -3,10 +3,10 @@ import type { Note } from "./note.ts";
 
 export const db = new Database(Deno.env.get("SQLITE_PATH") ?? "notes.db");
 try {
+  db.exec("PRAGMA busy_timeout=10000");
   db.exec("PRAGMA journal_mode=WAL");
-  db.exec("PRAGMA busy_timeout=5000");
   const [row] = db.prepare("PRAGMA journal_mode").all<{ journal_mode: string }>();
-  console.log(`[db] journal_mode=${row.journal_mode}, busy_timeout=5000`);
+  console.log(`[db] journal_mode=${row.journal_mode}, busy_timeout=10000`);
 } catch (e) {
   console.error("[db] failed to set PRAGMAs:", e);
 }