feat(slicing): build-plate override in the SliceModal (#1337)

Slicing an STL via the integrated slicer always defaulted to whatever
  curr_bed_type lived in the chosen process preset (typically "Cool
  Plate"), which the slicer CLI rejected for high-temp filaments with
  "Plate 1: Cool Plate does not support filament 1". The user had no
  way to switch plates without cloning the preset in BambuStudio.

  The Slice modal now exposes a Build plate dropdown with the six
  canonical BambuStudio / OrcaSlicer plates (Cool Plate, Cool Plate
  SuperTack, Engineering Plate, High Temp Plate, Textured PEI Plate,
  Smooth PEI Plate) plus an "Auto (use process preset)" option that
  preserves the previous behavior. Positioned between Process profile
  and Filament rows so a long filament list never pushes it off the
  modal's scrolled viewport, and always enabled regardless of whether
  the user picked a Printer Preset Bundle.

  A new bed_type field on SliceRequest flows through both dispatch
  paths:
  - Resolved-preset path: _patch_process_bed_type overwrites
    curr_bed_type on the process JSON before forwarding to the sidecar.
    Works end-to-end today, no sidecar change needed.
  - Bundle dispatch path: slice_with_bundle adds a bedType form field
    to the sidecar multipart. The sidecar (maziggy/orca-slicer-api
    fork) needs a matching change to honor it as --curr_bed_type on
    the CLI invocation; until then the field is silently ignored and
    the slice runs with the bundle's default plate.

frontend/src/__tests__/components/SliceModal.test.tsx

@@ -138,11 +138,15 @@ describe('SliceModal', () => {
     await waitFor(() => {
       expect(screen.getByText('My Custom X1C')).toBeDefined();
     });
+    // 4 selects: printer, process, bed-type (#1337), filament. bed-type sits
+    // between process and filament — it overrides curr_bed_type on the
+    // process preset so the related controls cluster — and defaults to "".
     const selects = screen.getAllByRole('combobox') as HTMLSelectElement[];
-    expect(selects).toHaveLength(3);
+    expect(selects).toHaveLength(4);
     expect(selects[0].value).toBe('local:1');
     expect(selects[1].value).toBe('local:2');
-    expect(selects[2].value).toBe('local:3');
+    expect(selects[2].value).toBe('');
+    expect(selects[3].value).toBe('local:3');
 
     // Slice button is enabled because all three slots auto-defaulted and
     // the preview-slice query has resolved (mock returns immediately).
@@ -240,6 +244,65 @@ describe('SliceModal', () => {
     await waitFor(() => expect(onClose).toHaveBeenCalled());
   });
 
+  it('includes bed_type in the request when the user picks a non-auto plate (#1337)', async () => {
+    const onClose = vi.fn();
+    mockApi.sliceLibraryFile.mockResolvedValue({
+      job_id: 42,
+      status: 'pending',
+      status_url: '/api/v1/slice-jobs/42',
+    });
+
+    renderWithTracker({
+      source: { kind: 'libraryFile', id: 100, filename: 'Cube.stl' },
+      onClose,
+    });
+
+    await waitFor(() => expect(screen.getByText('My Custom X1C')).toBeDefined());
+
+    const user = userEvent.setup();
+    // Order with the dropdown now sits between Process and Filament:
+    // printer (0), process (1), bed-type (2), filament (3+). Find the
+    // bed-type select by name rather than positional index so this stays
+    // green if the layout adds another control around it.
+    const bedSelect = screen.getAllByRole('combobox').find((el) =>
+      (el as HTMLSelectElement).options[0]?.textContent?.toLowerCase().includes('auto'),
+    ) as HTMLSelectElement;
+    expect(bedSelect).toBeDefined();
+    await user.selectOptions(bedSelect, 'Textured PEI Plate');
+    await user.click(screen.getByRole('button', { name: /^Slice$/ }));
+
+    await waitFor(() => {
+      expect(mockApi.sliceLibraryFile).toHaveBeenCalledWith(
+        100,
+        expect.objectContaining({ bed_type: 'Textured PEI Plate' }),
+      );
+    });
+  });
+
+  it('omits bed_type when the user leaves it on Auto (no override)', async () => {
+    const onClose = vi.fn();
+    mockApi.sliceLibraryFile.mockResolvedValue({
+      job_id: 42,
+      status: 'pending',
+      status_url: '/api/v1/slice-jobs/42',
+    });
+
+    renderWithTracker({
+      source: { kind: 'libraryFile', id: 100, filename: 'Cube.stl' },
+      onClose,
+    });
+
+    await waitFor(() => expect(screen.getByText('My Custom X1C')).toBeDefined());
+
+    const user = userEvent.setup();
+    await user.click(screen.getByRole('button', { name: /^Slice$/ }));
+
+    await waitFor(() => {
+      const [, body] = vi.mocked(mockApi.sliceLibraryFile).mock.calls[0];
+      expect(body).not.toHaveProperty('bed_type');
+    });
+  });
+
   it('lets the user override the default and pick a Standard preset', async () => {
     const onClose = vi.fn();
     mockApi.sliceLibraryFile.mockResolvedValue({
@@ -603,8 +666,8 @@ describe('SliceModal', () => {
     });
 
     await waitFor(() => expect(screen.getByText('X1C')).toBeDefined());
-    // 1 printer + 1 process + 2 filament = 4 dropdowns.
-    expect(screen.getAllByRole('combobox')).toHaveLength(4);
+    // 1 printer + 1 process + 2 filament + 1 bed-type (#1337) = 5 dropdowns.
+    expect(screen.getAllByRole('combobox')).toHaveLength(5);
   });
 
   it('pre-picks each filament slot by matching colour metadata', async () => {
@@ -686,9 +749,11 @@ describe('SliceModal', () => {
 
     const user = userEvent.setup();
     const selects = screen.getAllByRole('combobox') as HTMLSelectElement[];
-    // Slots 0 (printer) and 1 (process) are auto-picked. Slots 2 and 3 are
-    // the two filament dropdowns. Swap slot-2 (was black) to white.
-    await user.selectOptions(selects[2], 'cloud:F-WHITE');
+    // Order: 0 printer, 1 process, 2 bed-type, 3 filament-1, 4 filament-2
+    // (#1337). Auto-picks land on printer/process/filaments; bed-type
+    // defaults to "". Swap filament-1 (index 3) from the auto-picked black
+    // to white.
+    await user.selectOptions(selects[3], 'cloud:F-WHITE');
     await user.click(screen.getByRole('button', { name: /^Slice$/ }));
 
     await waitFor(() => {
@@ -884,12 +949,14 @@ describe('SliceModal', () => {
 
     await waitFor(() => expect(screen.getByText('X1C')).toBeDefined());
 
-    // Both filament rows render — 1 printer + 1 process + 2 filament = 4.
+    // Both filament rows render — 1 printer + 1 process + 1 bed-type +
+    // 2 filament (#1337) = 5. bed-type sits at index 2, filament slots
+    // follow at 3 and 4.
     const selects = screen.getAllByRole('combobox') as HTMLSelectElement[];
-    expect(selects).toHaveLength(4);
+    expect(selects).toHaveLength(5);
     // Slot 1 (used) is editable, slot 2 (not used) is disabled.
-    expect(selects[2].disabled).toBe(false);
-    expect(selects[3].disabled).toBe(true);
+    expect(selects[3].disabled).toBe(false);
+    expect(selects[4].disabled).toBe(true);
     // The disabled row's label calls out why it's disabled.
     expect(screen.getByText(/not used by this plate/i)).toBeDefined();
   });