v3: api/ gets one layout rule and keeps to it, and whatever crosses the wire is defined once, in shared/ — api/model/interfaces.ts and src/model.ts declared the same 40 types by hand and had drifted: the error envelope, email required on one side and optional on the other, Invitee/InviteTreeEntry and LinkPreview/UrlPreviewResponse for one shape each. The validation limits, the role permissions, the chat length cap, the @mention pattern and the Bandcamp and YouTube player responses were copied too, behind "keep in sync" comments. shared/ now holds them once, one file per domain (api, category, chat, comment, dump, follow, mention, notification, permissions, player, playlist, search, user, validation, ws), and imports nothing from either half. The server sends Dates; the client reads Wire<T>, the same type with every Date an ISO string, and turns it back with src/utils/shared/deserialize.ts. APIErrorCode becomes a const object, since the frontend's erasableSyntaxOnly rejects an enum. The shared types showed two real gaps: the avatar upload and GET /api/users/me return the full self user and the frontend read them as public users, and a stored session may predate media tokens, so the client keeps it as its own Session type. The backend rule: each folder holds one kind of module, each file is named after its domain. routes/ parse and answer; services/ hold the logic and every SQL query (lib/auth.ts's token check moves to user-service); remote/ is the only place that fetches from other sites — the guarded fetch and the HTML scraping out of rich-content-service, public-address, the Bandcamp and YouTube resolvers, the link providers, the image proxy (fetch, checks and cache, out of routes/preview.ts) and the Twemoji glyphs (out of lib/site-icons.ts). model/ holds per table a row type, its guard and its mappers; validators/ the request guards; db/connection.ts the handle and transaction(), db/startup.ts the purges and default admin that db.ts ran on import, called at the same moment. Tests mirror the source one file per module, test/<layer>/<module>.test.ts, with shared/'s under shared/test/ (deno task test runs both); the test that covered the bandcamp and soundcloud providers together is two now, and the backend can() has its own, so 202 tests. deno lint src/ is clean too: window.* becomes globalThis.*, and test bodies and act() callbacks that never awaited lose their async. The README states the rule. No behaviour changes; the catalogues only move their source references.

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

api/db/connection.ts

@@ -0,0 +1,36 @@
+import { DatabaseSync } from "node:sqlite";
+import { DB_PATH } from "../config.ts";
+import { runMigrations } from "./migrate.ts";
+import { runStartupTasks } from "./startup.ts";
+
+export const db = new DatabaseSync(DB_PATH);
+// WAL lets readers run alongside a writer, and with synchronous = NORMAL a
+// commit no longer waits on an fsync (a crash can lose the last transactions,
+// never corrupt the file). busy_timeout covers the init/migration scripts and
+// the test harness opening the same file.
+db.exec(`
+  PRAGMA journal_mode = WAL;
+  PRAGMA synchronous = NORMAL;
+  PRAGMA busy_timeout = 5000;
+  PRAGMA foreign_keys = ON;
+`);
+runMigrations(db);
+await runStartupTasks(db);
+
+/**
+ * Runs `fn` inside one transaction: several writes commit together (and cost
+ * one commit rather than one each), and a throw rolls them all back. Nested
+ * calls join the outer transaction.
+ */
+export function transaction<T>(fn: () => T): T {
+  if (db.isTransaction) return fn();
+  db.exec("BEGIN;");
+  try {
+    const result = fn();
+    db.exec("COMMIT;");
+    return result;
+  } catch (err) {
+    db.exec("ROLLBACK;");
+    throw err;
+  }
+}

api/db/startup.ts

@@ -0,0 +1,52 @@
+import { randomBytes, scryptSync } from "node:crypto";
+import type { DatabaseSync } from "node:sqlite";
+import {
+  ATTACHMENTS_DIR,
+  ORPHANED_ATTACHMENTS_RETENTION_HOURS,
+  UNUSED_INVITES_RETENTION_DAYS,
+} from "../config.ts";
+
+/**
+ * Housekeeping run once when the database is opened, after the migrations:
+ * drops what has expired, and seeds the default admin on an empty instance.
+ */
+export async function runStartupTasks(db: DatabaseSync): Promise<void> {
+  // Purge expired/used password reset tokens
+  db.prepare(
+    `DELETE FROM password_reset_tokens WHERE expires_at < datetime('now') OR used_at IS NOT NULL;`,
+  ).run();
+
+  // Purge expired unused invites
+  db.prepare(
+    `DELETE FROM invites WHERE used_at IS NULL AND created_at < datetime('now', '-${UNUSED_INVITES_RETENTION_DAYS} days');`,
+  ).run();
+
+  // Prune orphaned attachments (uploaded but never linked to a resource) older than 1 hour
+  const orphanedAttachments = db.prepare(
+    `SELECT id FROM attachments WHERE resource_id IS NULL AND created_at < datetime('now', '-${ORPHANED_ATTACHMENTS_RETENTION_HOURS} hour');`,
+  ).all() as { id: string }[];
+  if (orphanedAttachments.length > 0) {
+    for (const { id } of orphanedAttachments) {
+      await Deno.remove(`${ATTACHMENTS_DIR}/${id}`).catch(() => {});
+    }
+    db.prepare(
+      `DELETE FROM attachments WHERE resource_id IS NULL AND created_at < datetime('now', '-${ORPHANED_ATTACHMENTS_RETENTION_HOURS} hour');`,
+    ).run();
+  }
+
+  // Create default admin user if no users exist
+  const userCount = db.prepare(`SELECT COUNT(*) as count FROM users`).get() as {
+    count: number;
+  };
+  if (userCount.count === 0) {
+    const salt = randomBytes(16).toString("hex");
+    const hash = scryptSync("admin", salt, 64).toString("hex");
+    const passwordHash = `${hash}.${salt}`;
+    db.prepare(
+      `INSERT INTO users (id, username, password_hash, role, created_at, email) VALUES (?, 'admin', ?, 'admin', datetime('now'), 'admin@localhost')`,
+    ).run(crypto.randomUUID(), passwordHash);
+    console.log(
+      "Created default admin user (username: admin, password: admin)",
+    );
+  }
+}