fix(ams): ams_box_mapping mit Platzhaltern für fehlende Paint-Indizes auffüllen

Drucker interpretiert ams_box_mapping als geordnete Liste (Eintrag N = TN).
Bei Drucken die T0 nicht nutzen wurden die Einträge um 1 verschoben,
sodass T2 (rot) auf den Slot von T3 (weiß) zeigte.

Fixes #78

NIGHTLY_CHANGELOG.md

@@ -1,11 +1,4 @@
 ## Changes in this build
 
-- Unified axes control panel: XY and Z merged into one card, shared step size selector (0.1 / 1 / 5 / 10 mm) plus custom mm input field, Home XY/Z buttons placed directly below their respective pads
-- Language selector moved from header bar to Settings → Appearance
-- Filament mismatch detection: Upload-and-Print is intercepted when GCode material differs from the loaded AMS slot — slot mapper dialog opens automatically to correct the assignment before printing
-- Spoolman: assign a spool per AMS slot directly in the AMS status tab (dropdown per slot tile) and in the Filaments settings tab (dedicated assignment card)
-- Fix: filament profiles now isolated per printer in multi-printer setups — configuring one printer no longer overwrites the other (PR #75 by @walterioo)
-- Fix: printer dropdown and switch link now navigate to each printer's own bridge URL (same-origin, no cross-instance profile bleed)
-- Fix: Spoolman sync rate label corrected — 0 means sync at end of print, not disabled (Issue #76)
-- Slot color editor: Pickr color picker (HSV wheel + hex input), recent color swatches (up to 16, saved in browser), and "Copy color from slot" dropdown for identical backup spool setup (Issue #73)
-- UI: unified dropdown and input field styling across all settings panels
+- Fix: wrong filament slot used in multicolor prints when T0 is unused — AMS box mapping now includes placeholder entries for all paint indices so the printer correctly matches T1/T2/T3 tool changes to the right slots (Issue #78)
+- Fix: Spoolman spool-slot assignment now persisted to config.ini and restored on bridge restart

kobrax_moonraker_bridge.py

@@ -1601,16 +1601,32 @@ class KobraXBridge:
         loaded = loaded_slots
         if loaded is None:
             loaded = self._select_loaded_slots_for_print(warn_on_empty_default=warn_on_empty_default)
-        return [
-            {
-                "paint_index": pidx,
-                "ams_index": self._slot_to_print_ams_index(gidx),
-                "paint_color": [255, 255, 255, 255],
-                "ams_color": self._slot_color_rgba(s),
-                "material_type": s.get("type", "PLA"),
-            }
-            for pidx, (gidx, s) in enumerate(loaded)
-        ]
+        if not loaded:
+            return []
+        loaded_map = {gidx: s for gidx, s in loaded}
+        max_idx = max(loaded_map.keys())
+        # Drucker interpretiert ams_box_mapping als geordnete Liste (Eintrag N = TN).
+        # Fehlende Slots müssen als Platzhalter rein, sonst verschiebt sich alles.
+        result = []
+        for i in range(max_idx + 1):
+            if i in loaded_map:
+                s = loaded_map[i]
+                result.append({
+                    "paint_index": i,
+                    "ams_index": self._slot_to_print_ams_index(i),
+                    "paint_color": [255, 255, 255, 255],
+                    "ams_color": self._slot_color_rgba(s),
+                    "material_type": s.get("type", "PLA"),
+                })
+            else:
+                result.append({
+                    "paint_index": i,
+                    "ams_index": self._slot_to_print_ams_index(i),
+                    "paint_color": [255, 255, 255, 255],
+                    "ams_color": [255, 255, 255, 255],
+                    "material_type": "PLA",
+                })
+        return result
 
     def _build_assigned_ams_box_mapping(self, assignments: list) -> tuple[list[dict], int, int]:
         """Build print mapping from UI filament assignments.