feat(wm): add global layout_defaults for per-layout default options

Adds a top-level layout_defaults setting that defines default
layout_options and layout_options_rules per layout. Workspaces without
their own layout_options or layout_options_rules automatically inherit
the global defaults. If a workspace defines either setting, all global
defaults for that layout are fully replaced.

komorebi-layouts/src/default_layout.rs

@@ -1,3 +1,5 @@
+use std::collections::HashMap;
+
 use clap::ValueEnum;
 use serde::Deserialize;
 use serde::Serialize;
@@ -54,7 +56,7 @@ pub fn validate_ratios(ratios: &[f32]) -> [Option<f32>; MAX_RATIOS] {
 }
 
 #[derive(
-    Clone, Copy, Debug, Serialize, Deserialize, Eq, PartialEq, Display, EnumString, ValueEnum,
+    Clone, Copy, Debug, Serialize, Deserialize, Eq, PartialEq, Hash, Display, EnumString, ValueEnum,
 )]
 #[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
 /// A predefined komorebi layout
@@ -250,6 +252,21 @@ pub struct GridLayoutOptions {
     pub rows: usize,
 }
 
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+/// Per-layout default options entry for the `layout_defaults` global setting.
+/// Contains both base layout options and threshold-based layout options rules.
+pub struct LayoutDefaultEntry {
+    /// Default layout options for this layout
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub layout_options: Option<LayoutOptions>,
+    /// Threshold-based layout options rules in the format of threshold => options.
+    /// When container count >= threshold, the highest matching threshold's options
+    /// fully replace the base `layout_options`.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub layout_options_rules: Option<HashMap<usize, LayoutOptions>>,
+}
+
 impl DefaultLayout {
     pub fn leftmost_index(&self, len: usize) -> usize {
         match self {