Phase 36: add studio mixer channel strips and refresh screenshots

screenshots/README.md

@@ -1,16 +1,18 @@
 # xtc screenshots
 
-Captured from the Phase 35 FLTK application on 2026-10-28, using a virtual X11
+Captured from the Phase 36 FLTK application on 2026-10-28, using a virtual X11
 screen. Images show actual rendered widgets, without mockups or image edits.
 
 [View the contact sheet](overview.png).
 
-The arrangement uses `examples/projects/modern-session.xtc`. The audio view adds
-a temporary generated waveform. Mixer automation and loop selections are staged
-for these captures. Plugin views use the repository's LADSPA, CLAP, VST2 and
-VST3 test fixtures; these are demonstration plugins, not commercial instruments.
-Preferences show application defaults and the staged loop. No user configuration
-or example project was overwritten.
+The arrangement uses `examples/projects/modern-session.xtc`. Mixer captures add
+a bus, routing, pan/level settings and automation. The playing view shows actual
+JACK callback meters; additional captures show the minimum 1220 × 720 layout and
+a larger session scrolled to its final channels, with the master monitor pinned.
+The audio view adds a temporary generated waveform. Plugin views use the
+repository's LADSPA, CLAP, VST2 and VST3 test fixtures; these are demonstration
+plugins, not commercial instruments. Preferences show application defaults and
+the staged loop. No user configuration or example project was overwritten.
 
 - [Sequencer loop](01-sequencer-loop.png)
 - [Mixer automation](02-mixer-automation.png)
@@ -33,3 +35,6 @@ or example project was overwritten.
 - [Clap instrument descriptors](19-clap-instrument-descriptors.png)
 - [Vst2 instrument descriptors](20-vst2-instrument-descriptors.png)
 - [Vst3 instrument descriptors](21-vst3-instrument-descriptors.png)
+- [Mixer playing](22-mixer-playing.png)
+- [Mixer minimum size](23-mixer-minimum-size.png)
+- [Mixer scrolled session](24-mixer-scrolled-session.png)