fix: bugs surfaced by new gtest coverage

- html.cpp: rgba() colors parsed with setRedF/GreenF/BlueF (0-1) while the
  writer emits 0-255 integers, so semi-transparent text colors lost their
  RGB on round-trip; parse with integer setters instead
- CLIProgressDialog: percentage padding compared normalized progress
  (0.0-1.0) against 10/100, so padding was always fully applied; compute
  the percentage first
- TimelineUndoPointer BlockTrimCommand: remove_block_from_graph_ was
  never initialized (UB on redo)
- TimelineUndoGeneral TransitionRemoveCommand: track_ was never
  initialized; GetRelevantProject() could dereference it before redo()
- ProjectLoadTask::Run(): failure path deleted project_ without
  resetting it, leaving GetLoadedProject() dangling

app/common/html.cpp

@@ -356,9 +356,9 @@ QTextCharFormat Html::ReadCharFormat(const QXmlStreamAttributes &attributes)
 						QStringList rgba = vals_only.split(',');
 						if (rgba.size() == 4) {
 							QColor c;
-							c.setRedF(rgba.at(0).toDouble());
-							c.setGreenF(rgba.at(1).toDouble());
-							c.setBlueF(rgba.at(2).toDouble());
+							c.setRed(rgba.at(0).toInt()); // Writer emits 0-255 RGB (CSS rgba() convention)
+							c.setGreen(rgba.at(1).toInt());
+							c.setBlue(rgba.at(2).toInt());
 							c.setAlphaF(rgba.at(3).toDouble());
 							fmt.setForeground(c);
 						}