fix: dashboard broker badge reflects BROKER env (PAPER · TRADIER etc.)

Badge text was hardcoded to ALPACA; _broker_block now reports the active
broker name and derives paper/live from the Tradier sandbox host when
BROKER=tradier, keeping the base-URL-truth rule from plan 007.

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

api/main.py

@@ -86,12 +86,22 @@ def _command_bus_enabled() -> bool:
 def _broker_block() -> dict:
     """Broker truth for the LIVE badge, derived from the base URL the services
     already have (not the execution_mode literal, which lied). Alpaca's paper host
-    is ``paper-api.alpaca.markets``; anything else is live money."""
+    is ``paper-api.alpaca.markets``; Tradier's sandbox host starts with
+    ``sandbox.``; anything else is live money."""
     from urllib.parse import urlparse as _urlparse
 
+    if os.environ.get("BROKER", "alpaca").strip().lower() == "tradier":
+        url = os.environ.get("TRADIER_BASE_URL") or (
+            "https://api.tradier.com/v1"
+            if os.environ.get("TRADIER_ENV", "sandbox").strip().lower() == "live"
+            else "https://sandbox.tradier.com/v1")
+        host = _urlparse(url).hostname or url
+        return {"name": "TRADIER", "base_url_host": host,
+                "is_paper": host.startswith("sandbox.")}
     url = os.environ.get("ALPACA_BASE_URL") or "https://paper-api.alpaca.markets"
     host = _urlparse(url).hostname or url
-    return {"base_url_host": host, "is_paper": host.startswith("paper-api")}
+    return {"name": "ALPACA", "base_url_host": host,
+            "is_paper": host.startswith("paper-api")}
 
 
 def _eastern_session_date():

api/static/dashboard.html

@@ -1422,7 +1422,8 @@ function render(d) {
   const broker = d.broker || {};
   const isPaper = broker.is_paper !== false;   // default to paper when unknown
   const badge = $("mode-badge");
-  badge.textContent = isPaper ? "PAPER · ALPACA" : "LIVE · ALPACA";
+  const brokerName = broker.name || "ALPACA";
+  badge.textContent = (isPaper ? "PAPER · " : "LIVE · ") + brokerName;
   badge.className = "badge " + (isPaper ? "paper" : "live");
   const acct0 = (d.accounts || [])[0] || {};
   badge.title = (broker.base_url_host || "") + (acct0.account_id ? " · " + acct0.account_id : "");