feat: Add OSINT features (v0.1.2)

- MAC vendor lookup (IEEE OUI database)
- BLE company_id to manufacturer mapping
- Device profile enrichment in API responses
- Export endpoints: devices.csv, devices.json, alerts.csv, probes.csv
- Auto-populate vendor on device creation
- CLI command: flask download-oui
- Makefile target: make oui

13 tests passing

src/esp32_web/utils/oui.py

@@ -0,0 +1,87 @@
+"""MAC OUI vendor lookup."""
+import csv
+import logging
+import os
+from pathlib import Path
+
+log = logging.getLogger(__name__)
+
+# OUI database path
+OUI_DB_PATH = Path(os.environ.get('OUI_DB_PATH', '/var/lib/esp32-web/oui.csv'))
+OUI_DB_URL = 'https://standards-oui.ieee.org/oui/oui.csv'
+
+# In-memory cache
+_oui_cache: dict[str, str] = {}
+_loaded = False
+
+
+def _normalize_mac(mac: str) -> str:
+    """Extract OUI prefix (first 6 hex chars) from MAC."""
+    clean = mac.upper().replace(':', '').replace('-', '').replace('.', '')
+    return clean[:6] if len(clean) >= 6 else ''
+
+
+def load_oui_db(path: Path | None = None) -> int:
+    """Load OUI database from CSV file."""
+    global _oui_cache, _loaded
+
+    if path is None:
+        path = OUI_DB_PATH
+
+    if not path.exists():
+        log.warning('OUI database not found: %s', path)
+        return 0
+
+    _oui_cache.clear()
+    count = 0
+
+    try:
+        with open(path, 'r', encoding='utf-8') as f:
+            reader = csv.DictReader(f)
+            for row in reader:
+                # IEEE CSV format: Registry,Assignment,Organization Name,...
+                assignment = row.get('Assignment', '').strip().upper()
+                org = row.get('Organization Name', '').strip()
+                if assignment and org:
+                    _oui_cache[assignment] = org
+                    count += 1
+    except Exception as e:
+        log.exception('Error loading OUI database: %s', e)
+        return 0
+
+    _loaded = True
+    log.info('Loaded %d OUI entries from %s', count, path)
+    return count
+
+
+def lookup_vendor(mac: str) -> str | None:
+    """Lookup vendor by MAC address."""
+    global _loaded
+
+    if not _loaded:
+        load_oui_db()
+
+    oui = _normalize_mac(mac)
+    if not oui:
+        return None
+
+    return _oui_cache.get(oui)
+
+
+def download_oui_db(path: Path | None = None) -> bool:
+    """Download OUI database from IEEE."""
+    import urllib.request
+
+    if path is None:
+        path = OUI_DB_PATH
+
+    path.parent.mkdir(parents=True, exist_ok=True)
+
+    try:
+        log.info('Downloading OUI database from %s', OUI_DB_URL)
+        urllib.request.urlretrieve(OUI_DB_URL, path)
+        log.info('OUI database saved to %s', path)
+        return True
+    except Exception as e:
+        log.exception('Error downloading OUI database: %s', e)
+        return False