chore: prune boilerplate and refresh stale docs

- Remove 257 redundant per-definition comment stubs across the package
- Drop dead nonlocal declarations in autoslicer_detection.py
- Document the swapped flag and swap_left_right in architecture docs
- Remove unsupported 'legacy override' claims from autotune/runtime docs

scanslicer/canvas_render.py

@@ -3,9 +3,7 @@ from PySide6.QtCore import QRectF, Qt
 from PySide6.QtGui import QColor, QFont, QPainter, QPen
 
 
-# CanvasRenderMixin: class definition for ScanSlicer behavior.
 class CanvasRenderMixin:
-    # paintEvent: function definition for ScanSlicer behavior.
     def paintEvent(self, event):
         painter = QPainter(self)
         painter.fillRect(self.rect(), self.OFF_CANVAS_COLOR)