fix(vp): broadcast archive_created so Archives page refreshes live (#1282)

  Real-printer prints broadcast archive_created from the MQTT print_start
  handler, which the Archives page listens for to invalidate its query
  cache. The VP file-receive paths created the archive in the DB but
  never emitted the event, so the new card only appeared after a tab
  switch triggered refetch-on-focus.

  Added a small _broadcast_archive_created helper on VirtualPrinterInstance
  and called it from _archive_file (immediate mode) and _add_to_print_queue
  (queue mode). Review mode is unaffected — it creates a PendingUpload,
  not a PrintArchive. Broadcast errors are swallowed at debug level so a
  transient WebSocket issue can't break the file-receive flow.

backend/app/services/virtual_printer/manager.py

@@ -269,6 +269,7 @@ class VirtualPrinterInstance:
                 )
                 if archive:
                     logger.info("[VP %s] Archived: %s - %s", self.name, archive.id, archive.print_name)
+                    await self._broadcast_archive_created(archive)
                     try:
                         file_path.unlink()
                     except OSError:
@@ -437,6 +438,7 @@ class VirtualPrinterInstance:
                     db.add(queue_item)
                     await db.commit()
                     logger.info("[VP %s] Added to queue: %s", self.name, queue_item.id)
+                    await self._broadcast_archive_created(archive)
                     try:
                         file_path.unlink()
                     except OSError:
@@ -447,6 +449,28 @@ class VirtualPrinterInstance:
         except Exception as e:
             logger.error("Error adding to print queue: %s", e)
 
+    async def _broadcast_archive_created(self, archive) -> None:
+        """Notify connected clients that a new archive exists.
+
+        Real-printer prints get this from main.py's MQTT print_start handler;
+        VP-uploaded prints need their own broadcast or the Archives page stays
+        stale until the user switches tabs (#1282).
+        """
+        try:
+            from backend.app.core.websocket import ws_manager
+
+            await ws_manager.send_archive_created(
+                {
+                    "id": archive.id,
+                    "printer_id": archive.printer_id,
+                    "filename": archive.filename,
+                    "print_name": archive.print_name,
+                    "status": archive.status,
+                }
+            )
+        except Exception as e:
+            logger.debug("[VP %s] archive_created broadcast failed: %s", self.name, e)
+
     @staticmethod
     def _extract_plate_id(file_path: Path) -> int | None:
         """Extract plate index from 3MF slice_info.config."""

backend/tests/unit/services/test_virtual_printer.py

@@ -217,6 +217,67 @@ class TestVirtualPrinterInstance:
 
             assert "verify_job" not in instance._pending_files
 
+    @pytest.mark.asyncio
+    async def test_archive_file_broadcasts_archive_created(self, tmp_path):
+        """#1282: VP immediate-mode archives must broadcast archive_created so
+        the Archives page refreshes without a tab switch. Real-printer prints
+        get this via main.py's MQTT print_start handler; the VP path used to
+        skip the broadcast entirely."""
+        from backend.app.services.virtual_printer.manager import VirtualPrinterInstance
+
+        mock_db = AsyncMock()
+        mock_db.commit = AsyncMock()
+        mock_session_factory = MagicMock()
+        mock_session_ctx = AsyncMock()
+        mock_session_ctx.__aenter__ = AsyncMock(return_value=mock_db)
+        mock_session_ctx.__aexit__ = AsyncMock(return_value=False)
+        mock_session_factory.return_value = mock_session_ctx
+
+        inst = VirtualPrinterInstance(
+            vp_id=30,
+            name="ImmediateBroadcast",
+            mode="immediate",
+            model="C12",
+            access_code="12345678",
+            serial_suffix="391800030",
+            base_dir=tmp_path,
+            session_factory=mock_session_factory,
+        )
+
+        file_path = tmp_path / "test.3mf"
+        file_path.write_bytes(b"fake3mf")
+
+        mock_archive = MagicMock()
+        mock_archive.id = 99
+        mock_archive.printer_id = None
+        mock_archive.filename = "test.3mf"
+        mock_archive.print_name = "test"
+        mock_archive.status = "archived"
+
+        with (
+            patch(
+                "backend.app.api.routes.settings.get_setting",
+                new_callable=AsyncMock,
+                return_value=None,
+            ),
+            patch(
+                "backend.app.services.archive.ArchiveService.archive_print",
+                new_callable=AsyncMock,
+                return_value=mock_archive,
+            ),
+            patch(
+                "backend.app.core.websocket.ws_manager.send_archive_created",
+                new_callable=AsyncMock,
+            ) as mock_broadcast,
+        ):
+            await inst._archive_file(file_path, "192.168.1.100")
+
+        mock_broadcast.assert_awaited_once()
+        payload = mock_broadcast.await_args.args[0]
+        assert payload["id"] == 99
+        assert payload["filename"] == "test.3mf"
+        assert payload["status"] == "archived"
+
     # ========================================================================
     # Tests for auto_dispatch
     # ========================================================================
@@ -294,6 +355,68 @@ class TestVirtualPrinterInstance:
         queue_item = added_items[0]
         assert queue_item.manual_start is False
 
+    @pytest.mark.asyncio
+    async def test_add_to_print_queue_broadcasts_archive_created(self, tmp_path):
+        """#1282: VP queue-mode uploads must broadcast archive_created so the
+        Archives page picks up the new entry live. Pre-fix the page only
+        refreshed when the user manually switched tabs."""
+        from backend.app.services.virtual_printer.manager import VirtualPrinterInstance
+
+        mock_db = AsyncMock()
+        mock_db.add = MagicMock()
+        mock_db.commit = AsyncMock()
+        mock_session_factory = MagicMock()
+        mock_session_ctx = AsyncMock()
+        mock_session_ctx.__aenter__ = AsyncMock(return_value=mock_db)
+        mock_session_ctx.__aexit__ = AsyncMock(return_value=False)
+        mock_session_factory.return_value = mock_session_ctx
+
+        inst = VirtualPrinterInstance(
+            vp_id=31,
+            name="QueueBroadcast",
+            mode="print_queue",
+            model="C12",
+            access_code="12345678",
+            serial_suffix="391800031",
+            auto_dispatch=True,
+            base_dir=tmp_path,
+            session_factory=mock_session_factory,
+        )
+
+        file_path = tmp_path / "test.3mf"
+        file_path.write_bytes(b"fake3mf")
+
+        mock_archive = MagicMock()
+        mock_archive.id = 77
+        mock_archive.printer_id = None
+        mock_archive.filename = "test.3mf"
+        mock_archive.print_name = "test"
+        mock_archive.status = "archived"
+
+        with (
+            patch(
+                "backend.app.api.routes.settings.get_setting",
+                new_callable=AsyncMock,
+                return_value=None,
+            ),
+            patch(
+                "backend.app.services.archive.ArchiveService.archive_print",
+                new_callable=AsyncMock,
+                return_value=mock_archive,
+            ),
+            patch(
+                "backend.app.core.websocket.ws_manager.send_archive_created",
+                new_callable=AsyncMock,
+            ) as mock_broadcast,
+        ):
+            await inst._add_to_print_queue(file_path, "192.168.1.100")
+
+        mock_broadcast.assert_awaited_once()
+        payload = mock_broadcast.await_args.args[0]
+        assert payload["id"] == 77
+        assert payload["print_name"] == "test"
+        assert payload["status"] == "archived"
+
     @pytest.mark.asyncio
     async def test_add_to_print_queue_with_auto_dispatch_off(self, tmp_path):
         """Verify queue items have manual_start=True when auto_dispatch=False."""