feat: make SOCKS5 proxy configurable per adapter

Add `proxy` config option to server (IRC), teams, telegram, and mumble
sections. IRC defaults to false (preserving current direct-connect
behavior); all others default to true. The `derp.http` module now
accepts `proxy=True/False` on urlopen, create_connection,
open_connection, and build_opener -- when false, uses stdlib directly.

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

tests/test_telegram.py

@@ -764,3 +764,23 @@ class TestTelegramBotConfig:
     def test_admins_coerced_to_str(self):
         bot = _make_bot(admins=[111, 222])
         assert bot._admins == ["111", "222"]
+
+    def test_proxy_default_true(self):
+        bot = _make_bot()
+        assert bot._proxy is True
+
+    def test_proxy_disabled(self):
+        config = {
+            "telegram": {
+                "enabled": True,
+                "bot_token": "t",
+                "poll_timeout": 1,
+                "proxy": False,
+                "admins": [],
+                "operators": [],
+                "trusted": [],
+            },
+            "bot": {"prefix": "!", "rate_limit": 2.0, "rate_burst": 5},
+        }
+        bot = TelegramBot("test", config, PluginRegistry())
+        assert bot._proxy is False