Add start, stop, and finish job actions

- POST /jobs/{id}/start: modal picks from idle/offline printers,
  sets job → printing, printer → printing, logs "Job started on {name}"
- POST /jobs/{id}/stop: job → queued, clears printer_id + started_at,
  printer → idle, logs "Job stopped (was on {name})"
- POST /jobs/{id}/finish: job → done, sets finished_at + duration_minutes,
  printer → idle, logs "Job finished on {name}"
- Job detail shows Start / Stop+Finish buttons based on current status
- All printers currently printing are excluded from the Start printer picker

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

app/routers/ui.py

@@ -260,6 +260,9 @@ def job_detail(job_id: int, request: Request, db: Session = Depends(get_db)):
         "materials": available_materials() or MATERIALS,
         "colors": available_colors() or COLORS,
         "all_statuses": [s.value for s in JobStatus],
+        "available_printers": db.query(Printer).filter(
+            Printer.status != PrinterStatus.printing
+        ).order_by(Printer.name).all(),
     })
 
 
@@ -294,6 +297,68 @@ def edit_job(
     return RedirectResponse(url=f"/jobs/{job_id}", status_code=HTTP_303_SEE_OTHER)
 
 
+@router.post("/jobs/{job_id}/start")
+def start_job(job_id: int, printer_id: int = Form(...), db: Session = Depends(get_db)):
+    from fastapi import HTTPException
+    job = db.query(PrintJob).filter(PrintJob.id == job_id).first()
+    if not job:
+        raise HTTPException(404, "Job not found")
+    printer = db.query(Printer).filter(Printer.id == printer_id).first()
+    if not printer:
+        raise HTTPException(404, "Printer not found")
+
+    job.status = JobStatus.printing
+    job.printer_id = printer_id
+    job.started_at = datetime.now()
+    printer.status = PrinterStatus.printing
+
+    db.add(JobLog(job_id=job_id, message=f"Job started on {printer.name}"))
+    db.commit()
+    return RedirectResponse(url=f"/jobs/{job_id}", status_code=HTTP_303_SEE_OTHER)
+
+
+@router.post("/jobs/{job_id}/stop")
+def stop_job(job_id: int, db: Session = Depends(get_db)):
+    from fastapi import HTTPException
+    job = db.query(PrintJob).filter(PrintJob.id == job_id).first()
+    if not job:
+        raise HTTPException(404, "Job not found")
+
+    printer_name = job.printer.name if job.printer else "unknown printer"
+    if job.printer:
+        job.printer.status = PrinterStatus.idle
+
+    job.status = JobStatus.queued
+    job.printer_id = None
+    job.started_at = None
+
+    db.add(JobLog(job_id=job_id, message=f"Job stopped (was on {printer_name})"))
+    db.commit()
+    return RedirectResponse(url=f"/jobs/{job_id}", status_code=HTTP_303_SEE_OTHER)
+
+
+@router.post("/jobs/{job_id}/finish")
+def finish_job(job_id: int, db: Session = Depends(get_db)):
+    from fastapi import HTTPException
+    job = db.query(PrintJob).filter(PrintJob.id == job_id).first()
+    if not job:
+        raise HTTPException(404, "Job not found")
+
+    now = datetime.now()
+    job.status = JobStatus.done
+    job.finished_at = now
+    if job.started_at:
+        job.duration_minutes = max(1, int((now - job.started_at).total_seconds() / 60))
+
+    printer_name = job.printer.name if job.printer else "unknown printer"
+    if job.printer:
+        job.printer.status = PrinterStatus.idle
+
+    db.add(JobLog(job_id=job_id, message=f"Job finished on {printer_name}"))
+    db.commit()
+    return RedirectResponse(url=f"/jobs/{job_id}", status_code=HTTP_303_SEE_OTHER)
+
+
 @router.post("/jobs/{job_id}/analyse")
 def analyse_job_file(job_id: int, db: Session = Depends(get_db)):
     from fastapi import HTTPException

app/templates/job_detail.html

@@ -25,6 +25,29 @@
   </button>
 </div>
 
+{# ── Job actions ── #}
+{% set s = job.status.value %}
+{% if s == 'queued' %}
+<div class="mb-4">
+  <button class="btn btn-success btn-sm" data-bs-toggle="modal" data-bs-target="#startModal">
+    <i class="bi bi-play-fill me-1"></i>Start Job
+  </button>
+</div>
+{% elif s == 'printing' %}
+<div class="d-flex gap-2 mb-4">
+  <form method="POST" action="/jobs/{{ job.id }}/finish">
+    <button type="submit" class="btn btn-success btn-sm">
+      <i class="bi bi-check-lg me-1"></i>Finish
+    </button>
+  </form>
+  <form method="POST" action="/jobs/{{ job.id }}/stop">
+    <button type="submit" class="btn btn-outline-warning btn-sm">
+      <i class="bi bi-stop-fill me-1"></i>Stop
+    </button>
+  </form>
+</div>
+{% endif %}
+
 <div class="row g-3 mb-4">
 
   {# ── Job info ── #}
@@ -312,4 +335,41 @@
     </div>
   </div>
 </div>
+
+{# ── Start Job Modal ── #}
+{% if job.status.value == 'queued' %}
+<div class="modal fade" id="startModal" tabindex="-1">
+  <div class="modal-dialog">
+    <div class="modal-content bg-dark border-secondary">
+      <form method="POST" action="/jobs/{{ job.id }}/start">
+        <div class="modal-header border-secondary">
+          <h6 class="modal-title text-white">Start Job on Printer</h6>
+          <button type="button" class="btn-close btn-close-white" data-bs-dismiss="modal"></button>
+        </div>
+        <div class="modal-body">
+          {% if available_printers %}
+          <label class="form-label text-secondary small">Select 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>
+            {% for p in available_printers %}
+            <option value="{{ p.id }}">{{ p.name }}{% if p.location %} · {{ p.location }}{% endif %} ({{ p.status.value }})</option>
+            {% endfor %}
+          </select>
+          {% else %}
+          <p class="text-warning mb-0">
+            <i class="bi bi-exclamation-triangle me-1"></i>All printers are currently busy.
+          </p>
+          {% endif %}
+        </div>
+        <div class="modal-footer border-secondary">
+          <button type="button" class="btn btn-secondary btn-sm" data-bs-dismiss="modal">Cancel</button>
+          <button type="submit" class="btn btn-success btn-sm" {% if not available_printers %}disabled{% endif %}>
+            <i class="bi bi-play-fill me-1"></i>Start
+          </button>
+        </div>
+      </form>
+    </div>
+  </div>
+</div>
+{% endif %}
 {% endblock %}