feat(slicer): Slicer Pipelines — save & reuse a preset bundle in one click (#1425 PR A)

The SliceModal forces the user to pick four slots every time (printer /
process / filament(s) / bed type). For fleet production that's tedious
and error-prone. Pipelines let an operator save a named bundle and apply
it with one click on the next file.

PR A is bundle-and-management only. PR B adds single-target dispatch,
PR C adds multi-copy batch with capability-matched fanout. Future-PR
columns (target_kind / target_printer_id / target_model_class /
fanout_strategy) ship in this migration so PR B+ is code-only, not a
schema bump.

Backend
- New model SlicerPipeline + slicer_pipelines table; soft-delete via
  is_deleted so PR B+ run history can still resolve metadata.
- Pydantic schemas reuse the existing PresetRef shape from
  schemas/slicer.py.
- CRUD routes at /api/v1/slicer-pipelines/ — list (newest first by id
  DESC), create (201), get-by-id, partial PUT, soft-delete (204).
- Three new permissions: PIPELINES_READ / PIPELINES_WRITE / PIPELINES_RUN.
  Administrators + Operators get all three; Viewers get READ.
  Backfill in seed_default_groups() so existing installs upgrade
  cleanly. All three denied to API keys for now.

Frontend
- Settings → Workflow splits into two horizontal sub-tabs mirroring
  the Authentication tab pattern: "Queue & Dispatch" (existing
  Workflow content) and "Pipelines" (new). URL deep-link via
  ?tab=queue&sub=pipelines.
- SlicerPipelinesPanel — list, inline rename, delete, stale-preset
  warning when a referenced preset no longer resolves.
- SliceModal gets "Apply pipeline ▾" + "Save as pipeline". Apply
  fills all four slot states; the filament list right-pads from
  current state so a pipeline with fewer entries than the current
  source's slot count keeps the existing tail.

frontend/scripts/check-i18n-parity.mjs

@@ -147,6 +147,7 @@ const DE_COGNATES = [
 
   'Pause', 'Power', 'System', 'Problem', 'Designer', 'Extruder', 'Firmware',
   'Material', 'Original', 'Position', 'Webhook', 'Workflow', 'Slicer',
+  'Pipeline', 'Pipelines', 'Filament {{n}}',  // #1425 — Slicer Pipelines (DE)
   'Region', 'Normal', 'Orange', 'Branch', 'Budget', 'Commit', 'Global',
   'Version', 'Slot', 'Live', 'Rate', 'Host', 'Trend', 'Min', 'Admin', 'Cloud',
   'Filament', 'Filaments', 'Software', 'Hardware', 'Avatar', 'Pin', 'Modal',
@@ -179,6 +180,7 @@ const FR_COGNATES = [
   'Filaments', 'Software', 'Hardware', 'Stop', 'Reset', 'Test', 'Code',
   'Token', 'Server', 'Port', 'Plate', 'Layer', 'Active', 'Total', 'Avatar',
   'Job', 'Modal', 'Pin', 'Pro', 'Mini', 'Studio', 'Excellent', 'Description',
+  'Pipeline', 'Pipelines', 'Filament {{n}}',  // #1425 — Slicer Pipelines (FR)
   'Action', 'Actions', 'Date', 'Type', 'Cache', 'Service', 'Configuration',
   'Archives', 'Maintenance', 'Notifications', 'Notification', 'Position',
   'Pause', 'Solution', 'Source', 'Version', 'Format', 'Documentation',
@@ -217,6 +219,7 @@ const IT_COGNATES = [
   'Bambu Cloud', 'Orca Cloud',  // brand names — same in every locale
   'AMS Filament Backup',  // Bambu Lab product/firmware feature name
   'Email',  // common loanword in Italian, used verbatim in UI labels
+  'Pipeline',  // #1425 — Slicer Pipelines (cognate in IT)
   'Status', 'Tag', 'Tags', 'Online', 'Offline', 'Standard', 'Filament',
   'Filaments', 'Software', 'Hardware', 'Stop', 'Reset', 'Test', 'Code',
   'Token', 'Server', 'Port', 'Plate', 'Layer', 'Modal', 'Pin', 'Pro', 'Mini',
@@ -260,6 +263,7 @@ const JA_COGNATES = [
 const PT_BR_COGNATES = [
   'Bambu Cloud', 'Orca Cloud',  // brand names — same in every locale
   'AMS Filament Backup',  // Bambu Lab product/firmware feature name
+  'Pipeline', 'Pipelines',  // #1425 — Slicer Pipelines (PT-BR)
   'Status', 'Tag', 'Tags', 'Online', 'Offline', 'Standard', 'Filament',
   'Software', 'Hardware', 'Stop', 'Reset', 'Test', 'Code', 'Token', 'Server',
   'Port', 'Plate', 'Layer', 'Modal', 'Pin', 'Pro', 'Mini', 'Studio', 'Cache',
@@ -332,6 +336,7 @@ const KO_COGNATES = [
 const ES_COGNATES = [
   'Bambu Cloud', 'Orca Cloud',  // brand names — same in every locale
   'AMS Filament Backup',  // Bambu Lab product/firmware feature name
+  'Pipeline', 'Pipelines',  // #1425 — Slicer Pipelines (ES)
   'Error', 'Firmware', 'General', 'Control', 'Total', 'total', 'Material',
   'Material:', 'Color', 'Hex', 'Local', 'Global', 'China', 'Editable',
   'Normal', 'Metal', 'Multicolor', 'Proxy', 'Host', 'Factor', 'Original',
@@ -353,6 +358,7 @@ const TR_COGNATES = [
   'Filament', 'Firmware', 'Disk', 'Hex', 'Test', 'Port', 'Model', 'Metal',
   'Bambu Cloud', 'Orca Cloud',  // brand names — same in every locale
   'AMS Filament Backup',  // Bambu Lab product/firmware feature name
+  'Pipeline', 'Filament {{n}}',  // #1425 — Slicer Pipelines (TR)
   'Min', 'Normal', 'Platform', 'Net', 'Trend', 'Commit', 'Global', 'Proxy',
   'N/A', 'email',
   'STARTTLS (Port 587)', 'SSL/TLS (Port 465)',