feat(11-02): PATCH /printers/{id} route handler and updated _render_printer_list

- Add PATCH /{printer_id} route with validation and in-place update
- Optional ip_address/port_name fall back to existing values when not sent
- updated_at set explicitly on save (datetime.now(UTC))
- Update _render_printer_list to include clients and driver_data in context
- Import Driver at module level for use in both handler and helper

imptune/api/printers.py

@@ -1,4 +1,4 @@
-"""Printer CRUD API — POST /printers, DELETE /printers/{id}."""
+"""Printer CRUD API — POST /printers, DELETE /printers/{id}, PATCH /printers/{id}."""
 from __future__ import annotations
 
 from collections import defaultdict
@@ -9,7 +9,7 @@ from fastapi.responses import HTMLResponse, RedirectResponse
 from fastapi.templating import Jinja2Templates
 from peewee import JOIN
 
-from imptune.db.models import Client, Printer
+from imptune.db.models import Client, Driver, Printer
 
 router = APIRouter(prefix="/printers")
 
@@ -31,6 +31,8 @@ def _error_response(message: str, status_code: int = 400) -> HTMLResponse:
 
 def _render_printer_list(request: Request) -> HTMLResponse:
     """Query printers with LEFT JOIN on client and render grouped partial."""
+    import json
+
     query = (
         Printer.select(Printer, Client)
         .join(Client, JOIN.LEFT_OUTER)
@@ -41,10 +43,17 @@ def _render_printer_list(request: Request) -> HTMLResponse:
         client_name = p.client.name if p.client_id else "Unassigned"
         grouped[client_name].append(p)
 
+    clients = list(Client.select().order_by(Client.name))
+    all_drivers = list(Driver.select().order_by(Driver.uploaded_at.desc()))
+    driver_data = [
+        {"driver": d, "names": json.loads(d.driver_desc) if d.driver_desc else []}
+        for d in all_drivers
+    ]
+
     return templates.TemplateResponse(
         request=request,
         name="partials/printer_list.html",
-        context={"grouped": grouped},
+        context={"grouped": grouped, "clients": clients, "driver_data": driver_data},
     )
 
 
@@ -112,3 +121,54 @@ def delete_printer(request: Request, printer_id: int) -> HTMLResponse:
         return _error_response(f"Printer {printer_id} not found.", status_code=404)
 
     return _render_printer_list(request)
+
+
+@router.patch("/{printer_id}", response_class=HTMLResponse)
+def update_printer(
+    request: Request,
+    printer_id: int,
+    name: str = Form(...),
+    ip_address: str = Form(""),
+    port_name: str = Form(""),
+    duplex_mode: str = Form("OneSided"),
+    color_mode: str = Form(""),
+    paper_size: str = Form("A4"),
+    collate: str = Form(""),
+    client_id: str = Form(""),
+    driver_id: str = Form(""),
+) -> HTMLResponse:
+    """Update an existing printer configuration in-place."""
+    from datetime import UTC, datetime
+
+    printer = Printer.get_or_none(Printer.id == printer_id)
+    if printer is None:
+        return _error_response(f"Printer {printer_id} not found.", status_code=404)
+
+    name = name.strip()
+    ip_address = ip_address.strip() or printer.ip_address
+    port_name = port_name.strip() or printer.port_name
+
+    if not name:
+        return _error_response("Printer name is required.")
+    if not ip_address:
+        return _error_response("IP address is required.")
+    if not port_name:
+        return _error_response("Port name is required.")
+    if duplex_mode not in _VALID_DUPLEX:
+        return _error_response(f"Invalid duplex mode: {duplex_mode}.")
+    if paper_size not in _VALID_PAPER:
+        return _error_response(f"Invalid paper size: {paper_size}.")
+
+    printer.name = name
+    printer.ip_address = ip_address
+    printer.port_name = port_name
+    printer.duplex_mode = duplex_mode
+    printer.color_mode = color_mode == "on"
+    printer.paper_size = paper_size
+    printer.collate = collate == "on"
+    printer.client = int(client_id) if client_id.strip() else None
+    printer.driver = int(driver_id) if driver_id.strip() else None
+    printer.updated_at = datetime.now(UTC).replace(tzinfo=None)
+    printer.save()
+
+    return _render_printer_list(request)