#1375 : refactor(proxy) Deprecate 'proxy' parameter in BrowserConfig and enhance proxy string parsing

- Updated ProxyConfig.from_string to support multiple proxy formats, including URLs with credentials.
- Deprecated the 'proxy' parameter in BrowserConfig, replacing it with 'proxy_config' for better flexibility.
- Added warnings for deprecated usage and clarified behavior when both parameters are provided.
- Updated documentation and tests to reflect changes in proxy configuration handling.

tests/memory/test_docker_config_gen.py

@@ -24,7 +24,7 @@ CASES = [
     # --- BrowserConfig variants ---
     "BrowserConfig()",
     "BrowserConfig(headless=False, extra_args=['--disable-gpu'])",
-    "BrowserConfig(browser_mode='builtin', proxy='http://1.2.3.4:8080')",
+    "BrowserConfig(browser_mode='builtin', proxy_config={'server': 'http://1.2.3.4:8080'})",
 ]
 
 for code in CASES: