Manage scraper proxy from the Settings page

- New "Scraper Proxy" tab: enable toggle, host/port/username/password/
  country, Save, and a Test Connection button that reports the live exit
  IP + country through the proxy
- Backend proxy config now lives in system_config (DB authoritative when
  booking_proxy_enabled is set; BOOKING_PROXY_* env vars are the fallback)
- Dedicated /config/proxy GET/POST/test endpoints; password is write-only
  (never returned, blank keeps the stored value) and masked in /config/system
- Surface proxy status keys in the read-only System tab

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

backend/services/booking_scraper.py

@@ -44,27 +44,38 @@ def get_scraper_backend(db: Session) -> ScraperBackend:
 
     backend_type = result.config_value if result and result.config_value else 'playwright_local'
 
-    if backend_type == 'playwright_local':
-        return PlaywrightLocalBackend()
-
-    elif backend_type == 'playwright_proxy':
-        # Get proxy config
-        proxy_result = db.execute(
-            text("""
-                SELECT config_key, config_value FROM system_config
-                WHERE config_key IN ('booking_scraper_proxy_url', 'booking_scraper_proxy_username', 'booking_scraper_proxy_password')
-            """)
-        )
-        proxy_config = {row.config_key: row.config_value for row in proxy_result.fetchall()}
-        return PlaywrightLocalBackend(proxy_config=proxy_config)
-
-    elif backend_type == 'apify':
+    if backend_type == 'apify':
         # Future: Apify backend
         raise NotImplementedError("Apify backend not yet implemented")
 
-    else:
+    if backend_type not in ('playwright_local', 'playwright_proxy'):
         logger.warning(f"Unknown backend type '{backend_type}', falling back to playwright_local")
-        return PlaywrightLocalBackend()
+
+    # Proxy configuration is managed in system_config (Settings page). When the
+    # 'booking_proxy_enabled' key is present the DB is authoritative; otherwise
+    # the backend falls back to the BOOKING_PROXY_* environment variables.
+    proxy_rows = db.execute(
+        text("""
+            SELECT config_key, config_value FROM system_config
+            WHERE config_key LIKE 'booking_proxy_%'
+        """)
+    ).fetchall()
+    proxy = {row.config_key: row.config_value for row in proxy_rows}
+
+    if 'booking_proxy_enabled' in proxy:
+        if proxy.get('booking_proxy_enabled') == 'true':
+            return PlaywrightLocalBackend(proxy_config={
+                'host': proxy.get('booking_proxy_host', ''),
+                'port': proxy.get('booking_proxy_port', '823'),
+                'username': proxy.get('booking_proxy_username', ''),
+                'password': proxy.get('booking_proxy_password', ''),
+                'country': proxy.get('booking_proxy_country', 'gb'),
+            })
+        # Explicitly disabled in the DB — direct connection, ignore env.
+        return PlaywrightLocalBackend(proxy_config={})
+
+    # No DB override — let the backend read BOOKING_PROXY_* env vars.
+    return PlaywrightLocalBackend()
 
 
 def get_scrape_config(db: Session) -> Optional[Dict[str, Any]]: