viewer: open a miniCBF sweep, the same way rugnux already does

The native miniCBF reader added for rugnux is a plain JFJochReader, so the viewer
only needed to be told which one to open a file with. JFJochImageReadingWorker held
a concrete JFJochHDF5Reader; it now holds both readers and a JFJochReader* pointing
at whichever the open file needs, chosen by JFJochCBFReader::CanRead. Naming any
frame opens the whole sweep - the reader's own template matcher decides which frames
belong to it, so a directory holding two sweeps or XDS auxiliary files is not spliced
together. The previous file is closed before the new one is opened, so switching
format between HDF5 and CBF in one session leaves nothing behind.

Everything the viewer draws already goes through JFJochReader and
JFJochReaderDataset, so nothing else had to move. The two HDF5-only features stay on
the HDF5 reader: calibration images, and the reprocessing snapshots, which are
metadata read back over the same images the reader is serving and have nothing to
attach to for a directory of CBFs. A raw sweep therefore shows geometry and pictures
with an empty run list, which is the state a live HTTP stream is already in.

Reprocessing jobs run on a CBF sweep too - JFJochProcessController opens its own
reader the same way, and Rugnux has handled a CBF source since the reader landed.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Lc5JG6kJqZoCWaoZ43JGTW

viewer/JFJochProcessController.cpp

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: GPL-3.0-only
 
 #include "JFJochProcessController.h"
+#include "../reader/JFJochCBFReader.h"
 #include "../reader/JFJochHDF5Reader.h"
 
 #include <QMetaType>
@@ -44,8 +45,17 @@ void JFJochProcessController::cancel() {
 void JFJochProcessController::run_(QString file_path, DiffractionExperiment experiment,
                                    PixelMask pixel_mask, ProcessConfig config) {
     try {
-        JFJochHDF5Reader reader;
-        reader.ReadFile(file_path.toStdString());
+        JFJochHDF5Reader hdf5_reader;
+        JFJochCBFReader cbf_reader;
+        JFJochReader *reader_ptr;
+        if (JFJochCBFReader::CanRead(file_path.toStdString())) {
+            cbf_reader.ReadFiles(file_path.toStdString());
+            reader_ptr = &cbf_reader;
+        } else {
+            hdf5_reader.ReadFile(file_path.toStdString());
+            reader_ptr = &hdf5_reader;
+        }
+        JFJochReader &reader = *reader_ptr;
 
         // Seed the live dataset with the experiment so the chart has geometry context; per-image
         // results are filled in by OnImageProcessed as the run progresses.