grow the frame, remove the bottom panel basin

the bottom panel had a basin or tray to make room for taller levers,
namely the Seimitsu LSX-NOBI that I really like. per its specs, the
lever needs 43.70mm internally, and the old values were too tight (55mm
- 19mm from panels - 2mm from lever plate = 43) so the bottom panel was
arbitrarily given a sunken portion (somewhat arbitrarily 2.5mm) to
compensate at the time, because I already had frames printed.

adding 2mm to the frame Z covers the difference (57mm - 10mm - 2mm =
45mm) and thus we don't need the bottom panel hack anymore. I also
suspect the bottom panel basin was slightly affecting it structurally,
so this may help that.

src/bottom-panel-inset.scad

@@ -7,10 +7,7 @@ include <parameters.scad>
 include <components.scad>
 
 module bottom_panel() {
-	difference() {
-		mirror([0, 0, 1]) panel();
-		translate([0, 0, panel_z/2]) cube([panel_x-40, panel_y-40, panel_z], center=true);
-	}
+	mirror([0, 0, 1]) panel();
 }
 
 bottom_panel();

src/parameters.scad

@@ -35,7 +35,7 @@ lever_plate_hole = 12;
 // base frame box. reminder: top of inside (including mounts) is chopped by panel_z for plates
 frame_x = 233;
 frame_y = 208;
-frame_z = 55;
+frame_z = 57;
 
 frame_center_to_neutrik = 70;