feat: Filament Track Switch (H2-series O2L-FTS) support

The Filament Track Switch (H2-series accessory, product code O2L-FTS) feeds
every AMS to both extruders through a two-track switch. Port full support
across the device layer, project config, and GUI.

Device / config:
- Model the switch-aware AMS binding (the set of extruders an AMS can feed
  and which input track A/B feeds it), switch readiness, the O2L-FTS firmware
  module, and the fun2 capability bit for checking a slice against installed
  hardware.
- Register has_filament_switcher and enable_filament_dynamic_map as project
  config that persists with the project and restores from a saved 3mf, and
  force both back to false on every project/printer/CLI load path. Live
  device sync is the only thing that sets them true.

GUI:
- Sidebar sync activates the switch from live device state, attributes each
  AMS to the extruder its input track feeds, shows a floating status icon
  (ready / not-calibrated), and surfaces a one-time tip / not-calibrated
  warning.
- Send dialog gains a non-blocking slice-vs-hardware mismatch warning and a
  blocking error when a slice needs dynamic nozzle mapping but the switch is
  missing or not set up.
- AMS load/unload guards, AMS-view routing glyph + un-calibrated banner +
  hidden external-spool road, and mapping-popup external-spool lockout.
- Filament pickers collapse the per-extruder split into a single deduplicated
  "AMS filaments" group with a smart-assign toggle when the switch is ready.
- Firmware-upgrade panel lists the O2L-FTS accessory and its version.
- Device-provided filament-change steps (ams.cfs) drive the change-step
  display when firmware sends them, including the three switch steps.
- "Load current filament" asks which extruder to feed via a
  FeedDirectionDialog when the switch is calibrated.

Inert without the accessory: every path is gated on the switch being
installed (MQTT aux bit 29, default off) or ready, both project flags default
false, and the per-extruder AMS attribution is byte-identical, so AMS state,
the send/load UI, and sliced g-code are unchanged for every printer that does
not report a Filament Track Switch.

src/slic3r/GUI/Tab.cpp

@@ -5636,6 +5636,18 @@ void TabPrinter::on_preset_loaded()
         if (use_default_nozzle_volume_type) {
             m_preset_bundle->project_config.option<ConfigOptionEnumsGeneric>("nozzle_volume_type")->values = current_printer.config.option<ConfigOptionEnumsGeneric>("default_nozzle_volume_type")->values;
         }
+
+        // Changing printer model drops any Filament Track Switch context from the previous
+        // printer; clear both device-derived flags so a switch-less printer never inherits a
+        // stale installed/active state (re-derived by device sync when a printer is connected).
+        if (auto* has_switcher = m_preset_bundle->project_config.opt<ConfigOptionBool>("has_filament_switcher"))
+            has_switcher->value = false;
+        if (auto* dynamic_map = m_preset_bundle->project_config.opt<ConfigOptionBool>("enable_filament_dynamic_map"))
+            dynamic_map->value = false;
+        // Orca: also clear the sidebar switcher status icon on printer-model change (mirrors BBS's
+        // reset_fila_switch on machine change); it re-derives from device sync once a printer connects.
+        if (wxGetApp().plater())
+            wxGetApp().plater()->sidebar().reset_fila_switch();
     }
 }