feat(CRIT-010): add zone-to-county mapping and county_id to oil_prices

Add ZONE_COUNTY_MAP for all 5 scraped states (42 zone-to-county entries).
Scraper now resolves county_id at startup and assigns it to each record.
Upsert logic deduplicates by (name, state, county_id) to prevent duplicates
when multiple zones map to the same county. Also adds County model for
DB lookups and fixes Rhode Island zone count (4, not 5).

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

fuel_scraper/http_client.py

@@ -0,0 +1,32 @@
+"""
+HTTP client module for making web requests.
+"""
+import logging
+import requests
+from bs4 import BeautifulSoup
+
+# Default headers to mimic a browser
+DEFAULT_HEADERS = {
+    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36'
+}
+
+REQUEST_TIMEOUT = 20
+
+
+def make_request(url: str) -> BeautifulSoup | None:
+    """
+    Fetch a URL and return a BeautifulSoup object.
+    
+    Args:
+        url: The URL to fetch
+        
+    Returns:
+        BeautifulSoup object if successful, None otherwise
+    """
+    try:
+        response = requests.get(url, headers=DEFAULT_HEADERS, timeout=REQUEST_TIMEOUT)
+        response.raise_for_status()
+        return BeautifulSoup(response.content, 'html.parser')
+    except requests.exceptions.RequestException as e:
+        logging.error(f"Error fetching {url}: {e}")
+        return None