btoperator: local instances launch with BT_PLATFORM=glass

The console's one-click local-instance launcher predates the unified build
and never set the platform env -- instances booted the DEV profile (no
PadRIO), so the legacy arrow-drive bridge owned the keyboard instead of the
bindings.txt keymap (arrows drove fwd/back/turn, Alt-reverse dead).  The
join bats already set it; now the operator's QProcess env does too.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tools/btoperator.py

@@ -715,6 +715,12 @@ class Operator(QMainWindow):
                 continue
             tag = pilots[r]["address"]
             env = QProcessEnvironment.systemEnvironment()
+            # ONE unified build (2026-07-22): the GLASS platform env is what
+            # arms the desktop input stack (PadRIO -> bindings.txt keymap,
+            # clickable cockpit).  Without it the instance boots the DEV
+            # profile and the legacy arrow-drive bridge takes the keyboard
+            # (user-reported: "launched with the wrong keymap again").
+            env.insert("BT_PLATFORM", "glass")
             if self.f_gauges.isChecked():
                 env.insert("BT_DEV_GAUGES", "1")
             if self.f_inside.isChecked():