Make printer optional on job creation — assigned when job starts

Migration 0005 makes print_jobs.printer_id nullable.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/models/print_job.py

@@ -22,7 +22,7 @@ class PrintJob(Base):
 
     id: Mapped[int] = mapped_column(primary_key=True)
     job_uuid: Mapped[str | None] = mapped_column(String(36), unique=True, default=lambda: str(_uuid.uuid4()))
-    printer_id: Mapped[int] = mapped_column(ForeignKey("printers.id"))
+    printer_id: Mapped[int | None] = mapped_column(ForeignKey("printers.id"))
     filament_id: Mapped[int | None] = mapped_column(ForeignKey("filaments.id"))
     name: Mapped[str] = mapped_column(String(200))
     customer: Mapped[str | None] = mapped_column(String(200))

app/routers/ui.py

@@ -141,7 +141,7 @@ def jobs_page(request: Request, q: str = "", db: Session = Depends(get_db)):
 
 @router.post("/jobs")
 async def create_job(
-    printer_id: int = Form(...),
+    printer_id: str = Form(""),
     customer: str = Form(""),
     filament_id: str = Form(""),
     notes: str = Form(""),
@@ -160,7 +160,7 @@ async def create_job(
         job_uuid=str(_uuid.uuid4()),
         name=Path(filename).stem if filename else (customer.strip() or "Unnamed"),
         file_name=filename,
-        printer_id=printer_id,
+        printer_id=int(printer_id) if printer_id else None,
         filament_id=int(filament_id) if filament_id else None,
         customer=customer.strip() or None,
         notes=notes.strip() or None,

app/templates/jobs.html

@@ -85,9 +85,9 @@
 
           <div class="row g-3">
             <div class="col-md-6">
-              <label class="form-label text-secondary small">Printer <span class="text-danger">*</span></label>
-              <select name="printer_id" class="form-select bg-dark border-secondary text-white" required>
-                <option value="">— select —</option>
+              <label class="form-label text-secondary small">Printer <span class="text-secondary fw-normal">(assigned when starting)</span></label>
+              <select name="printer_id" class="form-select bg-dark border-secondary text-white">
+                <option value="">— unassigned —</option>
                 {% for p in printers %}
                 <option value="{{ p.id }}">{{ p.name }}{% if p.location %} ({{ p.location }}){% endif %}</option>
                 {% endfor %}