feat(umbriel): enhance window bindings and monitor layouts

dot_config/umbriel/rules.toml

@@ -146,8 +146,8 @@ default_scratchpad = "lmstudio"
 
 # Presentation shared by every scratchpad resident: floating, centered on the
 # output, 48% × 77% of its usable area (1638×1109 on the ultrawide, the size
-# Fastmail was resized to; 819×799 on the laptop panel; 1229×1109 on the Studio
-# Display). Fractions rather than px so it fits the laptop's 1038px height.
+# Fastmail was resized to; 614×594 on the laptop panel; 1229×1109 on the Studio
+# Display). Fractions rather than px so it fits the laptop's 772px height.
 # Last, so it overrides default_floating = false from the translucent-apps
 # rule for Claude and Beeper.
 [[window_rule]]