Remove ib-trading-mode

[AlexCatarino]

The IB brokerage now infers the trading mode from ib-account (QuantConnect/Lean.Brokerages.InteractiveBrokers#270), so the ib-trading-mode internal input is no longer needed.

The modules-1.14.json change is git-ignored and must be applied to the CDN copy; the diff is in the comment below. Engine images that predate that brokerage PR still require the key.

🤖 Generated with Claude Code

[AlexCatarino]

Diff of lean/modules-1.14.json against the CDN copy:

--- a/lean/modules-1.14.json
+++ b/lean/modules-1.14.json
@@ -69,28 +69,6 @@
                     ]
                 },
                 {
-                    "id": "ib-trading-mode",
-                    "type": "internal-input",
-                    "value-options": [
-                        {
-                            "condition": {
-                                "dependent-config-id": "ib-account",
-                                "pattern": "^df|^du|^di",
-                                "type": "regex"
-                            },
-                            "value": "paper"
-                        },
-                        {
-                            "condition": {
-                                "dependent-config-id": "ib-account",
-                                "pattern": "^f|^i|^u",
-                                "type": "regex"
-                            },
-                            "value": "live"
-                        }
-                    ]
-                },
-                {
                     "help": "Your Interactive Brokers username",
                     "id": "ib-user-name",
                     "input-method": "prompt",