Replace project with current server release and Windows setup

Import the 2026-10-09 source release, Fastify/SQLite backend, restored source
assets, and analytics-enabled server build. Replace files from the previous
release while retaining the existing repository history.

Make builds portable across Windows and Linux, configure local startup,
normalize Windows static asset paths, and fix test fixture cleanup and file
URL handling. Exclude local environment settings, databases, dependencies,
validation output, and TypeScript build cache from version control.

Validation: npm ci, static and server builds, 106 arrival tests, and actual
local HTTP checks passed. The full suite passed 467 of 470 tests; three tests
still require QA fixtures omitted from the supplied release, documented in
README-서버실행.md.

server/db.mjs

@@ -0,0 +1,114 @@
+import Database from 'better-sqlite3';
+import { chmodSync, closeSync, existsSync, mkdirSync, openSync, readFileSync, statSync, unlinkSync } from 'node:fs';
+import { dirname } from 'node:path';
+import { privateDatabasePath } from './config.mjs';
+
+const INITIAL_SQL = readFileSync(new URL('./migrations/001-initial.sql', import.meta.url), 'utf8');
+const COLUMNS = {
+  visitors_daily: ['visitor_id', 'visit_date', 'first_seen_at', 'last_seen_at'],
+  arrivals: ['dog_id', 'first_arrived_at'],
+};
+const seoulDate = new Intl.DateTimeFormat('en-CA', { timeZone: 'Asia/Seoul', year: 'numeric', month: '2-digit', day: '2-digit' });
+
+export function monthRange(month) {
+  if (typeof month !== 'string' || !/^(?!0000)[0-9]{4}-(0[1-9]|1[0-2])$/.test(month)) throw new Error('Invalid month; use YYYY-MM');
+  const year = +month.slice(0, 4);
+  const number = +month.slice(5);
+  // Lexicographic upper sentinel keeps the valid 9999-12 month queryable.
+  const next = number < 12 ? `${month.slice(0, 4)}-${String(number + 1).padStart(2, '0')}` : year < 9999 ? `${String(year + 1).padStart(4, '0')}-01` : '9999-13';
+  return [`${month}-01`, `${next}-01`];
+}
+
+export function assertSchema(db) {
+  if (db.pragma('user_version', { simple: true }) !== 1) throw new Error('Unsupported database schema');
+  for (const [table, columns] of Object.entries(COLUMNS)) {
+    const actual = db.pragma(`table_info(${table})`);
+    if (actual.map(c => c.name).join() !== columns.join() || actual.some(c => c.type !== 'TEXT' || c.notnull !== 1)) throw new Error('Unsupported database schema');
+    const keys = actual.filter(c => c.pk).sort((a, b) => a.pk - b.pk).map(c => c.name);
+    if (keys.join() !== (table === 'arrivals' ? 'dog_id' : 'visitor_id,visit_date')) throw new Error('Unsupported database schema');
+  }
+}
+
+/** Exported for migration rollback verification against a disposable database. */
+export function migrateDatabase(db, migrations = [{ version: 1, sql: INITIAL_SQL }]) {
+  const current = db.pragma('user_version', { simple: true });
+  const latest = migrations.at(-1)?.version ?? 0;
+  if (current > latest) throw new Error('Unsupported database version');
+  db.transaction(() => {
+    let version = current;
+    for (const migration of migrations) {
+      if (migration.version <= version) continue;
+      if (migration.version !== version + 1) throw new Error('Invalid migration order');
+      db.exec(migration.sql);
+      db.pragma(`user_version = ${migration.version}`);
+      version = migration.version;
+    }
+  }).immediate();
+}
+
+function privateParent(path) {
+  const parent = dirname(path);
+  mkdirSync(parent, { recursive: true, mode: 0o700 });
+  if (process.platform !== 'win32' && (statSync(parent).mode & 0o077)) throw new Error('Database directory must be private');
+}
+function safeCount(row) {
+  if (!Number.isSafeInteger(row.count) || row.count < 0) throw new Error('Invalid aggregate');
+  return row.count;
+}
+
+export function openStore({ dbPath, now = () => new Date(), busyTimeoutMs = 1000 }) {
+  if (!Number.isInteger(busyTimeoutMs) || busyTimeoutMs < 0 || busyTimeoutMs > 10000) throw new Error('Invalid busy timeout');
+  const path = privateDatabasePath(dbPath);
+  privateParent(path);
+  if (!existsSync(path)) closeSync(openSync(path, 'wx', 0o600));
+  if (process.platform !== 'win32') chmodSync(path, statSync(path).mode & 0o600);
+  const db = new Database(path, { timeout: busyTimeoutMs });
+  try {
+    db.pragma('journal_mode = WAL');
+    migrateDatabase(db);
+    assertSchema(db);
+    const visit = db.prepare('INSERT INTO visitors_daily (visitor_id, visit_date, first_seen_at, last_seen_at) VALUES (?, ?, ?, ?) ON CONFLICT(visitor_id, visit_date) DO UPDATE SET last_seen_at = excluded.last_seen_at');
+    const arrival = db.prepare('INSERT INTO arrivals (dog_id, first_arrived_at) VALUES (?, ?) ON CONFLICT(dog_id) DO NOTHING');
+    const count = db.prepare('SELECT COUNT(*) AS count FROM arrivals');
+    const monthly = db.prepare('SELECT COUNT(DISTINCT visitor_id) AS count FROM visitors_daily WHERE visit_date >= ? AND visit_date < ?');
+    return {
+      recordVisit(visitorId) {
+        const at = now();
+        const timestamp = at.toISOString();
+        const parts = Object.fromEntries(seoulDate.formatToParts(at).map(p => [p.type, p.value]));
+        visit.run(visitorId, `${parts.year.padStart(4, '0')}-${parts.month}-${parts.day}`, timestamp, timestamp);
+      },
+      recordArrival(dogId) { arrival.run(dogId, now().toISOString()); },
+      arrivalCount() { return safeCount(count.get()); },
+      monthlyVisitors(month) { return safeCount(monthly.get(...monthRange(month))); },
+      backup(destination) { return backupDatabase(db, path, destination); },
+      close() { if (db.open) db.close(); },
+    };
+  } catch (error) { db.close(); throw error; }
+}
+
+export function openReadOnlyStore(dbPath) {
+  const path = privateDatabasePath(dbPath);
+  const db = new Database(path, { readonly: true, fileMustExist: true, timeout: 1000 });
+  try {
+    assertSchema(db);
+    const count = db.prepare('SELECT COUNT(*) AS count FROM arrivals');
+    const monthly = db.prepare('SELECT COUNT(DISTINCT visitor_id) AS count FROM visitors_daily WHERE visit_date >= ? AND visit_date < ?');
+    return {
+      arrivalCount() { return safeCount(count.get()); },
+      monthlyVisitors(month) { return safeCount(monthly.get(...monthRange(month))); },
+      backup(destination) { return backupDatabase(db, path, destination); },
+      close() { if (db.open) db.close(); },
+    };
+  } catch (error) { db.close(); throw error; }
+}
+
+async function backupDatabase(db, source, destination) {
+  const target = privateDatabasePath(destination);
+  if (target === source) throw new Error('Backup must use a different path');
+  privateParent(target);
+  // Reserve exclusively before the async backup, so an existing backup is never replaced.
+  closeSync(openSync(target, 'wx', 0o600));
+  try { await db.backup(target); }
+  catch (error) { try { unlinkSync(target); } catch {} throw error; }
+}