feat(engine): wire the per-filament volume-map producer pipeline

- Print::update_filament_maps_to_config takes filament/volume/nozzle
  maps, backfills an empty volume map from extruder types, rebuilds
  filament_map_2, re-expands the per-filament variant arrays, and
  recomputes retract overrides keyed by resolved slots
- grouping writes its result back in every non-sequential mode;
  manual multi-nozzle grouping validates the user mapping and raises a
  translatable error on deviation; the engine's concrete volume
  assignment is deliberately not merged yet (per-filament arrays are
  already consumed by filament id, so materializing High Flow now
  would change motion before the layer-aware resolvers land)
- Print::apply treats the three map keys as engine outputs in auto
  modes (erased from the diff and adopted), compares them against used
  filaments in manual mode, and keeps the pre-expansion snapshot in
  sync with the late normalization pass so rebuilt headers reflect the
  sliced state instead of resurrecting stale values
- volume/nozzle maps and extruder_nozzle_stats join the invalidation
  group of filament_map (wipe tower + skirt/brim)
- PresetBundle composes full configs with an optional per-filament
  volume map (plate map, else defaults derived from each extruder's
  flow type); project config keeps the map sized across filament
  count changes
- PartPlate stores per-plate volume/nozzle maps; Plater injects them
  at every slice-composition site (incl. g-code reload and wipe-tower
  estimation); BackgroundSlicingProcess reads engine results back to
  the plate in auto modes
- per-filament map trust guards relaxed to size-match everywhere now
  that every producer sizes the map; single-filament explicit flow
  assignments are honored
- tests: grouping volume maps stay concrete, merge semantics of
  update_used_filament_values, single-filament override honoring

Motion g-code is byte-identical fleet-wide including Hybrid projects
(19-fixture gate + repro determinism double-slice). Header deltas:
the map keys now dump real values, and stale pre-normalization values
(e.g. enable_prime_tower on single-used-filament prints) no longer
leak into the config block.

src/libslic3r/Format/bbs_3mf.cpp

@@ -4512,8 +4512,10 @@ void PlateData::parse_filament_info(GCodeProcessorResult *result)
                 if (m_curr_plater){
                     auto filament_volume_map = get_vector_from_string(value);
                     for (size_t idx = 0; idx < filament_volume_map.size(); ++idx) {
-                        // Only Standard(0)/High Flow(1) are currently supported; clamp any higher
-                        // volume-type (TPU High Flow/Hybrid) back to Standard until they are wired in.
+                        // The map feeds per-filament slot resolution and grouping. Clamp any
+                        // higher volume-type back to Standard(0) on load: Hybrid(2) is only an
+                        // in-memory grouping seed that is never persisted, and TPU High Flow(3)
+                        // is clamped with the same information loss on every load.
                         if (filament_volume_map[idx] > 1) {
                             filament_volume_map[idx] = 0;
                         }