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_teams.py

@@ -732,3 +732,28 @@ class TestTeamsBotPluginManagement:
         ok, msg = bot.reload_plugin("nonexistent")
         assert ok is False
         assert "not loaded" in msg
+
+
+class TestTeamsBotConfig:
+    def test_proxy_default_true(self):
+        bot = _make_bot()
+        assert bot._proxy is True
+
+    def test_proxy_disabled(self):
+        config = {
+            "teams": {
+                "enabled": True,
+                "bot_name": "derp",
+                "bind": "127.0.0.1",
+                "port": 8081,
+                "webhook_secret": "",
+                "incoming_webhook_url": "",
+                "proxy": False,
+                "admins": [],
+                "operators": [],
+                "trusted": [],
+            },
+            "bot": {"prefix": "!", "rate_limit": 2.0, "rate_burst": 5},
+        }
+        bot = TeamsBot("test", config, PluginRegistry())
+        assert bot._proxy is False