Fix dashboard tool to print 'output' job events, not just 'line'

Most useful compile output - including error text on a failed build -
arrives as event:output, not event:line. install() only handled line,
so a real compile failure came back with job result exit_code:2 and zero
printed error text, discovered on the first genuine failure it hit.

tools/gxepd2_dashboard/dashboard.py

@@ -120,7 +120,13 @@ async def install(configuration: str, timeout: float = 480) -> bool:
             if str(data.get("message_id")) != "2":
                 continue
             ev = data.get("event")
-            if ev == "line":
+            if ev in ("line", "output"):
+                # Most useful compile output (including error text on a
+                # failed build) actually arrives as "output" events, not
+                # "line" - a first version of this tool only handled
+                # "line" and silently printed nothing on either success or
+                # failure, discovered when a real compile failure came
+                # back with no error text at all (2026-09-19).
                 d = data.get("data")
                 if isinstance(d, str):
                     line = clean(d)