session logging, build-only mode, park splash, boot logo spinner

- Per-process stderr logging to /data/log2/{session}/ with time-safe
  directory naming (boot-xxx renamed once GPS/NTP sets clock)
- Aggregate session.log with major events (start/stop, transitions)
- 30-day log rotation cleanup on manager startup
- build_only.sh: compile without starting manager, non-blocking error
  display, kills stale processes
- build.py: copies updated spinner binary after successful build
- Onroad park mode: show splash screen when car is on but in park,
  switch to camera view when shifted to drive, honor screen on/off
- Spinner: full-screen boot logo background from /usr/comma/bg.jpg
  with white progress bar overlay
- Boot logo: auto-regenerate when boot_logo.png changes, 140% scale
- launch_openpilot.sh: cd to /data/openpilot for reliable execution
- launch_chffrplus.sh: kill stale text error displays on startup
- spinner shell wrapper: prefer freshly built _spinner over prebuilt

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

selfdrive/ui/qt/home.cc

@@ -61,19 +61,42 @@ void HomeWindow::showSidebar(bool show) {
 }
 
 void HomeWindow::updateState(const UIState &s) {
-  // const SubMaster &sm = *(s.sm);
   if (s.scene.started) {
     showDriverView(s.scene.driver_camera_timer >= 10, true);
+
+    // CLEARPILOT: show splash screen when onroad but in park
+    bool parked = s.scene.parked;
+    if (parked && !was_parked_onroad) {
+      // just shifted into park — show splash
+      slayout->setCurrentWidget(ready);
+    } else if (!parked && was_parked_onroad) {
+      // just shifted out of park — show onroad camera
+      slayout->setCurrentWidget(onroad);
+    }
+    was_parked_onroad = parked;
+
+    // CLEARPILOT: honor display on/off while showing splash in park
+    if (parked && ready->isVisible()) {
+      int screenMode = paramsMemory.getInt("ScreenDisaplayMode");
+      if (screenMode == 1) {
+        Hardware::set_display_power(false);
+      } else {
+        Hardware::set_display_power(true);
+      }
+    }
   }
 }
 
 void HomeWindow::offroadTransition(bool offroad) {
+  sidebar->setVisible(false);
   if (offroad) {
-    sidebar->setVisible(false);
+    was_parked_onroad = false;
     slayout->setCurrentWidget(ready);
   } else {
-    sidebar->setVisible(false);
-    slayout->setCurrentWidget(onroad);
+    // CLEARPILOT: start onroad in splash — updateState will switch to
+    // camera view once the car shifts out of park
+    was_parked_onroad = true;
+    slayout->setCurrentWidget(ready);
   }
 }