Scaffold project and implement config, DB schema/queries

- Set up package.json (ESM, scripts), tsconfig.json, vitest.config.ts
- Install runtime and dev dependencies
- Add CLAUDE.md with architecture notes and code quality rules
- Config module with env var parsing and JWT_SECRET validation
- DB schema: users + files tables with FK cascade
- DB queries: createUser, getUserBy*, createFile, getFileById, getFilesByUserId, deleteFile
- Tests for config, db/users, db/files (15 tests passing)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/config.ts

@@ -0,0 +1,34 @@
+export interface Config {
+  port: number;
+  host: string;
+  jwtSecret: string;
+  jwtExpiry: string;
+  dbPath: string;
+  uploadDir: string;
+  logFile: string;
+  maxFileSize: number;
+  baseUrl: string;
+  cookieSecure: boolean;
+  trustProxy: boolean;
+}
+
+export function loadConfig(): Config {
+  const jwtSecret = process.env.JWT_SECRET;
+  if (!jwtSecret) {
+    throw new Error('JWT_SECRET environment variable is required');
+  }
+
+  return {
+    port: parseInt(process.env.PORT ?? '3000', 10),
+    host: process.env.HOST ?? '0.0.0.0',
+    jwtSecret,
+    jwtExpiry: process.env.JWT_EXPIRY ?? '7d',
+    dbPath: process.env.DB_PATH ?? './data/nanodrop.db',
+    uploadDir: process.env.UPLOAD_DIR ?? './data/uploads',
+    logFile: process.env.LOG_FILE ?? './data/nanodrop.log',
+    maxFileSize: parseInt(process.env.MAX_FILE_SIZE ?? '104857600', 10),
+    baseUrl: process.env.BASE_URL ?? 'http://localhost:3000',
+    cookieSecure: process.env.COOKIE_SECURE === 'true',
+    trustProxy: process.env.TRUST_PROXY === 'true',
+  };
+}