feat: dual external spool support, AMS slot model filtering & pre-population

Backend:
- Add dual external spool support for H2D (vt_tray as list: Ext-L/Ext-R)
- Add cloud filament ID map endpoint (/cloud/filament-id-map)
- Fix RFID spool data erased by periodic AMS updates (skip tag matcher
  for RFID-tagged trays)
- Fix AMS slot config overwrites RFID spool state
- Fix K-profile selection corrupts existing profiles on X1C/P1S
- Resolve K-profiles filament name via cloud filament ID map
- Update print scheduler and usage tracker for dual external spools

Frontend:
- Add printer model filtering to ConfigureAmsSlotModal (cloud/local/builtin
  presets filtered by @BBL model suffix and compatible_printers)
- Add pre-population for configured slots (preset, color, K-profile)
- Add K-Profiles view with accurate filament name resolution
- Internationalize all ConfigureAmsSlotModal strings (en/de/fr/it/ja — 21 keys)
- Add 5 new ConfigureAmsSlotModal tests (model filtering, pre-selection,
  color pre-population, i18n)
- Update PrintersPage for dual external spool rendering

Docs:
- Update CHANGELOG, README, website features, and wiki AMS docs

frontend/src/hooks/useFilamentMapping.ts

@@ -41,22 +41,26 @@ export function buildLoadedFilaments(printerStatus: PrinterStatus | undefined):
     });
   });
 
-  // Add external spool if loaded
-  if (printerStatus?.vt_tray?.tray_type) {
-    const color = normalizeColor(printerStatus.vt_tray.tray_color);
-    filaments.push({
-      type: printerStatus.vt_tray.tray_type,
-      color,
-      colorName: getColorName(color),
-      amsId: -1,
-      trayId: 0,
-      isHt: false,
-      isExternal: true,
-      label: 'External',
-      globalTrayId: 254,
-      trayInfoIdx: printerStatus.vt_tray.tray_info_idx || '',
-      extruderId: hasDualNozzle ? 0 : undefined,
-    });
+  // Add external spool(s) if loaded
+  for (const extTray of printerStatus?.vt_tray ?? []) {
+    if (extTray.tray_type) {
+      const color = normalizeColor(extTray.tray_color);
+      const trayId = extTray.id ?? 254;
+      const hasDualExternal = (printerStatus?.vt_tray?.length ?? 0) > 1;
+      filaments.push({
+        type: extTray.tray_type,
+        color,
+        colorName: getColorName(color),
+        amsId: -1,
+        trayId: trayId - 254,
+        isHt: false,
+        isExternal: true,
+        label: hasDualExternal ? (trayId === 254 ? 'Ext-L' : 'Ext-R') : 'External',
+        globalTrayId: trayId,
+        trayInfoIdx: extTray.tray_info_idx || '',
+        extruderId: hasDualNozzle ? (trayId - 254) : undefined,
+      });
+    }
   }
 
   return filaments;