umbriel: scratchpad residents float as a centered 960px square instead of maximized

docs/desktop/umbriel.mdx

@@ -61,7 +61,7 @@ The Studio Display's phantom 640x480 connector, which niri switched off as `DP-5
 
 ## Scratchpads
 
-Named scratchpads replace Hyprland's `special:*` workspaces and `omarchy-toggle-scratch`. A window rule sends each app into its scratchpad when it opens; toggling an empty scratchpad runs `spawn_when_empty`. Shown scratchpads are maximized over a desktop dimmed to 0.6, on the output under the pointer.
+Named scratchpads replace Hyprland's `special:*` workspaces and `omarchy-toggle-scratch`. A window rule sends each app into its scratchpad when it opens; toggling an empty scratchpad runs `spawn_when_empty`. A shown scratchpad window floats as a 960 px square centered on the output under the pointer (`default_floating_size_px`, the last window rule in `rules.toml`; 960 fits the laptop panel's 1038 px usable height) over a desktop dimmed to 0.6. `animation.scratchpad.maximize` is off. The size is a default: a resident that was already open before the rule changed keeps its old geometry until it is reopened.
 
 | Scratchpad | App id | Launch | Keys |
 | --- | --- | --- | --- |
@@ -85,7 +85,7 @@ Named scratchpads replace Hyprland's `special:*` workspaces and `omarchy-toggle-
 | title `Picture-in-Picture` / `Picture in picture` | floating, unfocused, opaque, 24 px from the top-right of `eDP-1` |
 | YouTube and chat/mail/dashboard apps (`chromium`, Calendar, Discord, Slack, Gemini, Hermes, Todoist, Cloudflare web apps) | laptop panel, workspace 1, maximized |
 | `zed`, `obsidian`, sticky notes, `vacuumtube`, `Fladder`, `kitty`, `kitty-herdr`, `kitty-tmux` | Apple Studio Display |
-| the six scratchpad apps | their scratchpad |
+| the six scratchpad apps | their scratchpad, floating 960×960 centered |
 
 Noctalia's bar, panels, notifications, dock, OSD, and desktop widgets get blur through a layer rule.