feat(slicer): bundle-aware preview slice for accurate gram estimates

The SliceModal's preview slice runs against unsliced project files to
  discover per-plate AMS slot consumption. Until now it always used
  slice_without_profiles — accurate slot mapping (a model property) but
  gram numbers were derived from the file's embedded process settings,
  which can drift from the triplet the real print will use.

  When the caller provides a bundle id + printer/process/filament preset
  names, get_preview_filaments now routes through slice_with_bundle so
  the preview's gram numbers match what the real print will produce.
  Cache key picks up a bundle-context fingerprint so different bundle
  picks on the same file occupy distinct entries.

  Backend:
  - slice_preview.get_preview_filaments: optional bundle_* params
  - library.py + archives.py: forward params via /filament-requirements

  Frontend (forward-compat for the upcoming SliceModal Bundle tier):
  - api.getLibraryFileFilamentRequirements / getArchiveFilamentRequirements
    accept an optional 4th-arg bundle context object

frontend/src/api/client.ts

@@ -1171,6 +1171,20 @@ export interface SliceRequest {
   export_3mf?: boolean;
 }
 
+// GET /api/v1/slicer/bundles — Printer Preset Bundles imported from
+// BambuStudio's "File → Export → Export Preset Bundle" dialog. Each bundle
+// is a .bbscfg zip the user uploads once per printer, after which the
+// SliceModal can pick its inner presets by name (no re-upload per slice).
+// Backend: backend/app/api/routes/slicer_presets.py — bundle endpoints.
+export interface SlicerBundle {
+  id: string;
+  printer_preset_name: string;
+  printer: string[];
+  process: string[];
+  filament: string[];
+  version: string | null;
+}
+
 // GET /api/v1/slicer/presets — unified listing across cloud / local / standard.
 export type SlicerCloudStatus = 'ok' | 'not_authenticated' | 'expired' | 'unreachable';
 export interface UnifiedPreset {
@@ -3776,10 +3790,31 @@ export const api = {
   },
   getArchivePlates: (archiveId: number) =>
     request<ArchivePlatesResponse>(`/archives/${archiveId}/plates`),
-  getArchiveFilamentRequirements: (archiveId: number, plateId?: number, requestId?: string) => {
+  getArchiveFilamentRequirements: (
+    archiveId: number,
+    plateId?: number,
+    requestId?: string,
+    // Optional bundle context: when supplied, the backend's preview slice
+    // (run for unsliced project files) uses slice_with_bundle so gram
+    // numbers reflect the same triplet the real print will use. All four
+    // fields must be set for the bundle path to engage; partial context
+    // falls back to the embedded-settings preview without erroring.
+    bundle?: {
+      bundle_id: string;
+      printer_name: string;
+      process_name: string;
+      filament_names: string[];
+    },
+  ) => {
     const qs = new URLSearchParams();
     if (plateId !== undefined) qs.set('plate_id', String(plateId));
     if (requestId) qs.set('request_id', requestId);
+    if (bundle) {
+      qs.set('bundle_id', bundle.bundle_id);
+      qs.set('printer_name', bundle.printer_name);
+      qs.set('process_name', bundle.process_name);
+      qs.set('filament_names', bundle.filament_names.join(';'));
+    }
     return request<{
       archive_id: number;
       filename: string;
@@ -5141,10 +5176,28 @@ export const api = {
     }),
   getLibraryFilePlates: (fileId: number) =>
     request<LibraryFilePlatesResponse>(`/library/files/${fileId}/plates`),
-  getLibraryFileFilamentRequirements: (fileId: number, plateId?: number, requestId?: string) => {
+  getLibraryFileFilamentRequirements: (
+    fileId: number,
+    plateId?: number,
+    requestId?: string,
+    // Optional bundle context — see getArchiveFilamentRequirements above
+    // for the contract. Same shape so callers can share a builder helper.
+    bundle?: {
+      bundle_id: string;
+      printer_name: string;
+      process_name: string;
+      filament_names: string[];
+    },
+  ) => {
     const qs = new URLSearchParams();
     if (plateId !== undefined) qs.set('plate_id', String(plateId));
     if (requestId) qs.set('request_id', requestId);
+    if (bundle) {
+      qs.set('bundle_id', bundle.bundle_id);
+      qs.set('printer_name', bundle.printer_name);
+      qs.set('process_name', bundle.process_name);
+      qs.set('filament_names', bundle.filament_names.join(';'));
+    }
     return request<{
       file_id: number;
       filename: string;
@@ -5269,6 +5322,35 @@ export const api = {
   getSlicerPresets: () =>
     request<UnifiedPresetsResponse>('/slicer/presets'),
 
+  // Slicer Bundles (.bbscfg) — Printer Preset Bundles imported from BambuStudio.
+  // Settings → Slicer Bundles uploads/lists/deletes; the SliceModal picks
+  // presets by name from a chosen bundle (separate follow-up).
+  listSlicerBundles: () =>
+    request<SlicerBundle[]>('/slicer/bundles'),
+  importSlicerBundle: (file: File) => {
+    // The /slicer/bundles upload accepts multipart with field name "file"
+    // (matches the FastAPI route's UploadFile parameter). Bypass `request`
+    // because it always JSON-stringifies the body — multipart needs the
+    // browser to set the boundary in the Content-Type header.
+    const fd = new FormData();
+    fd.append('file', file);
+    return fetch(`${API_BASE}/slicer/bundles`, {
+      method: 'POST',
+      headers: authToken ? { 'Authorization': `Bearer ${authToken}` } : {},
+      body: fd,
+    }).then(async (res) => {
+      if (!res.ok) {
+        const err = await res.json().catch(() => ({}));
+        throw new Error(err.detail || `HTTP ${res.status}`);
+      }
+      return res.json() as Promise<SlicerBundle>;
+    });
+  },
+  deleteSlicerBundle: (bundleId: string) =>
+    request<void>(`/slicer/bundles/${encodeURIComponent(bundleId)}`, {
+      method: 'DELETE',
+    }),
+
   // Local Presets (OrcaSlicer imports)
   getLocalPresets: () =>
     request<LocalPresetsResponse>('/local-presets/'),