main: respect the elevation mask after applying offsets

This prevents offsets from being able to point below the elevation
mask. The way this is done should probably be reworked, but this whole
thing is such a messy hack anyway that, like, whatever, man.

src/main.zig

@@ -185,9 +185,21 @@ pub const RotInt = struct {
                 .el = self.requested_posture.el,
             };
             mangled.el = if (mangled.el > 90)
-                @min(mangled.el, 180 - self.conf.elevation_mask) - self.offsets.el
+                @max(
+                    @min(
+                        @min(mangled.el, 180 - self.conf.elevation_mask) - self.offsets.el,
+                        180 - self.conf.elevation_mask,
+                    ),
+                    90,
+                )
             else
-                @max(mangled.el, self.conf.elevation_mask) + self.offsets.el;
+                @min(
+                    @max(
+                        @max(mangled.el, self.conf.elevation_mask) + self.offsets.el,
+                        self.conf.elevation_mask,
+                    ),
+                    90,
+                );
 
             self.sendRotatorCommand(.{ .set_position = mangled });
         } else {