Model-based queue assignment with filament validation and queue notifications (#162)

Model-based queue assignment:
- Extract printer_model from sliced 3MF files during upload
- Display sliced-for model in archive view
- New queue mode: assign to "Any [Model]" instead of specific printer
- Scheduler auto-assigns to first idle printer of matching model
- Filament validation: only assign to printers with required filament types loaded
- Waiting reason display shows why jobs are waiting (e.g., "Waiting for filament: Printer1 (needs PLA)")
- "Waiting" status badge (purple) distinguishes from regular "Pending"

Queue notifications (7 new events):
- Job Added: When a job is added to queue
- Job Assigned: When a model-based job is assigned to a printer
- Job Started: When a queue job starts printing
- Job Waiting: When a job is waiting for filament (enabled by default)
- Job Skipped: When a job is skipped due to previous failure (enabled by default)
- Job Failed: When a job fails to start (enabled by default)
- Queue Complete: When all queued jobs finish

Backend changes:
- New columns: print_queue.target_model, print_queue.required_filament_types, print_queue.waiting_reason
- New columns: notification_providers.on_queue_job_* (7 event triggers)
- Notification templates for all queue events
- Scheduler validates filament compatibility before model-based assignment
- Queue API extracts filament types from 3MF when adding model-based items
- Local backup/restore includes queue notification settings

Frontend changes:
- TypeScript interfaces updated for new fields
- Queue page shows waiting reason and "Waiting" badge
- Notification settings includes "Print Queue" section with 7 toggles

Closes #162

frontend/src/components/NotificationProviderCard.tsx

@@ -398,6 +398,88 @@ export function NotificationProviderCard({ provider, onEdit }: NotificationProvi
                 </div>
               </div>
 
+              {/* Print Queue Events */}
+              <div className="space-y-2">
+                <p className="text-xs text-bambu-gray uppercase tracking-wide">Print Queue</p>
+
+                <div className="flex items-center justify-between">
+                  <div>
+                    <p className="text-sm text-white">Job Added</p>
+                    <p className="text-xs text-bambu-gray">Job added to queue</p>
+                  </div>
+                  <Toggle
+                    checked={provider.on_queue_job_added ?? false}
+                    onChange={(checked) => updateMutation.mutate({ on_queue_job_added: checked })}
+                  />
+                </div>
+
+                <div className="flex items-center justify-between">
+                  <div>
+                    <p className="text-sm text-white">Job Assigned</p>
+                    <p className="text-xs text-bambu-gray">Model-based job assigned to printer</p>
+                  </div>
+                  <Toggle
+                    checked={provider.on_queue_job_assigned ?? false}
+                    onChange={(checked) => updateMutation.mutate({ on_queue_job_assigned: checked })}
+                  />
+                </div>
+
+                <div className="flex items-center justify-between">
+                  <div>
+                    <p className="text-sm text-white">Job Started</p>
+                    <p className="text-xs text-bambu-gray">Queue job started printing</p>
+                  </div>
+                  <Toggle
+                    checked={provider.on_queue_job_started ?? false}
+                    onChange={(checked) => updateMutation.mutate({ on_queue_job_started: checked })}
+                  />
+                </div>
+
+                <div className="flex items-center justify-between">
+                  <div>
+                    <p className="text-sm text-white">Job Waiting</p>
+                    <p className="text-xs text-bambu-gray">Job waiting for filament</p>
+                  </div>
+                  <Toggle
+                    checked={provider.on_queue_job_waiting ?? true}
+                    onChange={(checked) => updateMutation.mutate({ on_queue_job_waiting: checked })}
+                  />
+                </div>
+
+                <div className="flex items-center justify-between">
+                  <div>
+                    <p className="text-sm text-white">Job Skipped</p>
+                    <p className="text-xs text-bambu-gray">Job skipped (previous failed)</p>
+                  </div>
+                  <Toggle
+                    checked={provider.on_queue_job_skipped ?? true}
+                    onChange={(checked) => updateMutation.mutate({ on_queue_job_skipped: checked })}
+                  />
+                </div>
+
+                <div className="flex items-center justify-between">
+                  <div>
+                    <p className="text-sm text-white">Job Failed</p>
+                    <p className="text-xs text-bambu-gray">Job failed to start</p>
+                  </div>
+                  <Toggle
+                    checked={provider.on_queue_job_failed ?? true}
+                    onChange={(checked) => updateMutation.mutate({ on_queue_job_failed: checked })}
+                  />
+                </div>
+
+                <div className="flex items-center justify-between">
+                  <div>
+                    <p className="text-sm text-white">Queue Complete</p>
+                    <p className="text-xs text-bambu-gray">All queue jobs finished</p>
+                  </div>
+                  <Toggle
+                    checked={provider.on_queue_completed ?? false}
+                    onChange={(checked) => updateMutation.mutate({ on_queue_completed: checked })}
+                  />
+                </div>
+              </div>
+
               {/* Quiet Hours */}
               <div className="space-y-2">
                 <div className="flex items-center justify-between">