feat(vp): per-VP "Save AMS mapping" toggle + reprint auto-apply

Lets a reprint reuse the AMS slot the slicer itself picked, instead of
re-deriving one from the file's static type/color.

When a Print Queue VP has "Save AMS mapping" on, the slicer's own
live-resolved ams_mapping (from the project_file MQTT command) is
persisted onto the archive as extra_data.slicer_ams_mapping. A later
reprint can reuse it via a new "Mapping" button in the filament-mapping
panel — one click snaps every slot to the saved pick, click again
reverts to auto-match. Archive cards and queue rows get an "AMS mapping
saved" badge so it's visible beforehand. add_to_queue also falls back
to the saved mapping automatically when the caller sends no explicit
ams_mapping (e.g. a plain reprint with no per-slot edits).

The queue item's own ams_mapping (used for that dispatch) is still
captured unconditionally whenever the slicer provides it — that part is
a correctness fix, not gated behind the toggle. Only the archive
persistence for future reprints is opt-in.

Split out from the original combined PR per review: this half is
genuinely opt-in and low-risk (#2684). The dispatch-time validation
gate that keeps a stored mapping honest (#1308) changes behaviour for
every existing user and will land as its own PR.

Review fixes applied:
- _extract_slicer_ams_mapping_json: dropped the unreachable `v is None`
  arm and rejected bool explicitly (isinstance(v, int) accepts bool).
- Translated the Russian docstring text to English.
- save_ams_mapping's model comment moved to a trailing comment on the
  column line, matching the file's convention.
- usingArchiveMapping now resets when the plate or archive changes, so
  the Mapping button can't read ON against a mapping it never applied.
- Translated "Click to change slot assignment" and "Re-read".
- add_to_queue's fallback is now called out explicitly in code comments
  and covered by three new integration tests (fallback fires, explicit
  mapping wins, unrelated extra_data doesn't false-trigger).

Closes #2684

frontend/src/components/PrintModal/FilamentMapping.tsx

@@ -1,4 +1,4 @@
-import { useMemo, useState } from 'react';
+import { useEffect, useMemo, useState } from 'react';
 import { useTranslation } from 'react-i18next';
 import { useQuery, useQueryClient } from '@tanstack/react-query';
 import { Circle, Check, AlertTriangle, RefreshCw, ChevronDown, ChevronUp, Palette } from 'lucide-react';
@@ -24,11 +24,50 @@ export function FilamentMapping({
   forceColorMatch,
   onForceColorMatchChange,
   plateLabel,
+  archiveAmsMapping,
 }: FilamentMappingProps & { defaultExpanded?: boolean }) {
   const { t } = useTranslation();
   const queryClient = useQueryClient();
   const [isRefreshing, setIsRefreshing] = useState(false);
   const [isExpanded, setIsExpanded] = useState(defaultExpanded);
+  // "Mapping" toggle (only shown when the archive has a saved slicer pick):
+  // ON selects every slot straight from `archiveAmsMapping`, bypassing the
+  // type/color auto-match entirely — same mechanism as a manual per-slot
+  // pick (`manualMappings`), just applied to every required slot at once.
+  // OFF removes exactly those overrides so the panel falls back to its
+  // normal auto-match, without touching any *other* manual picks the user
+  // made by hand.
+  const [usingArchiveMapping, setUsingArchiveMapping] = useState(false);
+
+  // Reset the toggle whenever the saved mapping it would apply changes — a
+  // different plate selection or a different archive entirely. Without this
+  // the button can read ON (green) from a previous archive/plate even though
+  // it was never pressed against the mapping currently in scope.
+  useEffect(() => {
+    setUsingArchiveMapping(false);
+  }, [archiveAmsMapping, plateLabel]);
+
+  const toggleArchiveMapping = () => {
+    if (!archiveAmsMapping || !filamentReqs?.filaments) return;
+    if (usingArchiveMapping) {
+      const next = { ...manualMappings };
+      for (const req of filamentReqs.filaments) {
+        if (req.slot_id > 0) delete next[req.slot_id];
+      }
+      onManualMappingChange(next);
+      setUsingArchiveMapping(false);
+      return;
+    }
+    const next = { ...manualMappings };
+    for (const req of filamentReqs.filaments) {
+      const idx = req.slot_id - 1;
+      if (req.slot_id > 0 && idx >= 0 && idx < archiveAmsMapping.length && archiveAmsMapping[idx] >= 0) {
+        next[req.slot_id] = archiveAmsMapping[idx];
+      }
+    }
+    onManualMappingChange(next);
+    setUsingArchiveMapping(true);
+  };
 
   // Fetch printer status
   const { data: printerStatus } = useQuery({
@@ -211,16 +250,33 @@ export function FilamentMapping({
       {isExpanded && (
         <div className="mt-2 bg-bambu-dark rounded-lg p-3 space-y-2">
           <div className="flex items-center justify-between mb-2">
-            <span className="text-xs text-bambu-gray">Click to change slot assignment</span>
-            <button
-              type="button"
-              onClick={handleRefresh}
-              className="flex items-center gap-1 px-2 py-0.5 text-xs rounded border border-bambu-gray/30 hover:border-bambu-gray hover:bg-bambu-dark-tertiary transition-colors text-bambu-gray hover:text-white"
-              disabled={isRefreshing}
-            >
-              <RefreshCw className={`w-3 h-3 ${isRefreshing ? 'animate-spin' : ''}`} />
-              <span>Re-read</span>
-            </button>
+            <span className="text-xs text-bambu-gray">{t('printModal.clickToChangeSlot')}</span>
+            <div className="flex items-center gap-1.5">
+              {archiveAmsMapping && (
+                <button
+                  type="button"
+                  onClick={toggleArchiveMapping}
+                  title={t('printModal.useArchiveMappingTooltip')}
+                  className={`flex items-center gap-1 px-2 py-0.5 text-xs rounded border transition-colors ${
+                    usingArchiveMapping
+                      ? 'border-bambu-green bg-bambu-green/10 text-bambu-green'
+                      : 'border-bambu-gray/30 hover:border-bambu-gray hover:bg-bambu-dark-tertiary text-bambu-gray hover:text-white'
+                  }`}
+                >
+                  <Check className="w-3 h-3" />
+                  <span>{t('printModal.useArchiveMapping')}</span>
+                </button>
+              )}
+              <button
+                type="button"
+                onClick={handleRefresh}
+                className="flex items-center gap-1 px-2 py-0.5 text-xs rounded border border-bambu-gray/30 hover:border-bambu-gray hover:bg-bambu-dark-tertiary transition-colors text-bambu-gray hover:text-white"
+                disabled={isRefreshing}
+              >
+                <RefreshCw className={`w-3 h-3 ${isRefreshing ? 'animate-spin' : ''}`} />
+                <span>{t('printModal.reRead')}</span>
+              </button>
+            </div>
           </div>
           {filamentComparison.map((item, idx) => {
             // #1717: surface the same per-slot force-color-match checkbox here

frontend/src/components/PrintModal/index.tsx

@@ -325,6 +325,13 @@ export function PrintModal({
   // Get sliced_for_model from archive or library file
   const slicedForModel = archiveDetails?.sliced_for_model || libraryFileDetails?.sliced_for_model || null;
 
+  // The archive's own saved AMS-slot pick from the slicer (see the "Save AMS
+  // mapping" virtual-printer setting) — undefined for library files or
+  // archives that predate the feature / had it off at print time.
+  const archiveSlicerAmsMapping = !isLibraryFile
+    ? (archiveDetails?.extra_data?.slicer_ams_mapping as number[] | undefined)
+    : undefined;
+
   // Fetch plates for archives
   const { data: archivePlatesData, isError: archivePlatesError } = useQuery({
     queryKey: ['archive-plates', archiveId],
@@ -1407,6 +1414,7 @@ export function PrintModal({
                 onForceColorMatchChange={(slotId, value) =>
                   setForceColorMatch((prev) => ({ ...prev, [slotId]: value }))
                 }
+                archiveAmsMapping={archiveSlicerAmsMapping}
               />
             )}
 

frontend/src/components/PrintModal/types.ts

@@ -224,6 +224,14 @@ export interface FilamentMappingProps {
    *  plate. Each plate prints its own subset of the file's slots and gets its
    *  own AMS mapping, so the panels have to be told apart. */
   plateLabel?: string;
+  /** The archive's own saved AMS-slot pick from the slicer
+   *  (`extra_data.slicer_ams_mapping`, written when the source virtual
+   *  printer has "Save AMS mapping" enabled) — position = slot_id-1, value =
+   *  global tray ID. When present, a "Mapping" toggle next to "Re-read" lets
+   *  the user select every slot from this array instead of the type/color
+   *  auto-match. Undefined/omitted when the archive has no saved mapping —
+   *  the toggle is hidden and behaviour is unchanged. */
+  archiveAmsMapping?: number[];
 }
 
 /**