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/DeviceCore/DevFilaSwitch.h

@@ -49,6 +49,11 @@ public:
 public:
     bool IsInstalled() const { return m_is_installed; };
 
+    // Ready once installed and every AMS has resolved both its extruder binding and its
+    // switcher track position from the device. The send dialog and sidebar sync UX only
+    // treat the switch as usable when this is true.
+    bool IsReady() const;
+
     std::optional<bool> IsInA_HasFilament() const { return m_in_a_has_filament; };
     std::optional<bool> IsInB_HasFilament() const { return m_in_b_has_filament; };
 
@@ -67,12 +72,6 @@ public:
     void Reset();
     void ParseFilaSwitchInfo(const nlohmann::json& print_jj);
 
-    // NOTE: an IsReady() accessor is intentionally omitted. It would walk
-    // GetFilaSystem()->GetAmsList() calling GetBindedExtruderSet()/GetSwitcherPos(),
-    // AMS filament-switch binding accessors Orca's DevFilaSystem does not yet carry.
-    // It is unused by the filament blacklist; port it alongside the filament-switch
-    // device-sync UI that needs those accessors.
-
 private:
     MachineObject* m_owner;