```python
# play.py
from playwright.async_api import async_playwright as aP
import xvfbwrapper, io, os
from db import DB

async def Page(browser='chromium', headless=True):
    if headless: xvfbwrapper.Xvfb().start()
    else: os.environ['DISPLAY'] = ':0'
    db = DB()

    playwright = await aP().start()
    browser = await getattr(playwright, browser).launch(headless=False)
    context = await browser.new_context(accept_downloads=True)
    context.set_default_timeout(0)

    async def save(response):
        if response.ok and not db.exists(url := response.url):
            db[url] = await response.body()
        
    async def load(route):
        if body := db[route.request.url]:
            return await route.fulfill(body=body)
        await route.continue_()

    context.on('response', save)
    await context.route('**/*', load)
    for block in ['**/*.gif', '**/css*.js']:
        await context.route(block, lambda route: route.abort())
        
    return await context.new_page()

if __name__ == "__main__":
    page = await Page()
    await page.goto('https://naver.com')
    await page.screenshot(path='screenshot.png')
```

```python
# db.py
import sqlite3, json

class DB(sqlite3.Connection):
    def __init__(self, db_name=".db.sqlite"):
        super().__init__(db_name)
        with self:
            self.execute('''
                CREATE TABLE IF NOT EXISTS kv_store
                (key TEXT PRIMARY KEY, value BLOB)
            ''')

    def __setitem__(self, key, value):
        if not isinstance(value, bytes): value = json.dumps(value)
        with self:
            cur = self.execute('''
                INSERT OR REPLACE INTO kv_store
                (key, value) VALUES (?, ?)
            ''', (key, value))
            return {"modified_count": cur.rowcount}

    def __getitem__(self, key):
        with self:
            result = self.execute('''
                SELECT value FROM kv_store
                WHERE key = ?
            ''', (key,)).fetchone()
        if result:
            if isinstance(result[0], str):
                try: return json.loads(result[0])
                except json.JSONDecodeError: pass
            return result[0]

    def delete(self, key):
        with self:
            cur = self.execute('''
                DELETE FROM kv_store 
                WHERE key = ?
            ''', (key,))
            return {"deleted_count": cur.rowcount}

    def keys(self, pattern='*'):
        pattern = pattern.translate(str.maketrans({
            '\\': '\\\\', '%': '\\%', '_': '\\_', '*': '%', '?': '_'
        }))
        with self:
            result = self.execute('''
                SELECT key FROM kv_store
                WHERE key LIKE ? ESCAPE '\\'
            ''', (pattern,)).fetchall()
        return [row[0] for row in result]

    def __repr__(self): return repr(self.keys())

    def exists(self, key):
        with self:
            cur = self.execute('''
                SELECT 1 FROM kv_store
                WHERE key = ?
                LIMIT 1
            ''', (key,))
            return bool(cur.fetchone())

if __name__ == '__main__':
    db = DB()

    # 문자열 저장 및 조회
    db['hello'] = 'world'
    print(db['hello'])  # 출력: world (str 타입)
    
    # 숫자 저장 및 조회
    db['number'] = 42
    print(db['number'])  # 출력: 42 (int 타입)
    
    # 바이너리 데이터 저장 및 조회
    db['binary'] = b'binary data'
    print(db['binary'])  # 출력: b'binary data' (bytes 타입)
    
    # 복잡한 객체 저장
    complex_obj = {'name': 'John', 'age': 30, 'city': 'New York'}
    db['complex'] = complex_obj
    loaded_obj = db['complex']
    print(loaded_obj)  # 출력: {'name': 'John', 'age': 30, 'city': 'New York'} (dict 타입)
    
    db['test_key'] = 'test_value'
    
    print(db.exists('test_key'))  # True
    print(db.exists('non_existent_key'))  # False

```