feat: configure collapsed sidebar startup state

refs #1463

3 files changed, 50 insertions, 1 deletions

diff --git a/src/app/mod.rs b/src/app/mod.rs
index 6ea84746..8909fb1f 100644
--- a/src/app/mod.rs
+++ b/src/app/mod.rs
@@ -602,7 +602,7 @@ impl App {
             mobile_width_threshold: config.ui.mobile_width_threshold,
             sidebar_width_source,
             sidebar_width_auto: false,
-            sidebar_collapsed: false,
+            sidebar_collapsed: config.ui.sidebar_start_collapsed,
             sidebar_collapsed_mode: config.ui.sidebar_collapsed_mode,
             sidebar_section_split,
             agent_panel_sort,
@@ -2374,6 +2374,17 @@ mod tests {
     }
 
     #[test]
+    fn startup_uses_configured_sidebar_state() {
+        let mut config = Config::default();
+        config.ui.sidebar_start_collapsed = true;
+        let (_api_tx, api_rx) = tokio::sync::mpsc::unbounded_channel();
+
+        let app = App::new(&config, true, None, api_rx, crate::api::EventHub::default());
+
+        assert!(app.state.sidebar_collapsed);
+    }
+
+    #[test]
     fn startup_uses_redraw_on_focus_gained_config() {
         let mut config = Config::default();
         config.ui.redraw_on_focus_gained = false;
@@ -2775,6 +2786,25 @@ mod tests {
     }
 
     #[test]
+    fn reload_config_does_not_reset_sidebar_to_startup_state() {
+        let _guard = config_env_lock().lock().unwrap();
+        let path = temp_config_path("reload-config-sidebar-start-collapsed");
+        std::fs::create_dir_all(path.parent().unwrap()).unwrap();
+        std::env::set_var(crate::config::CONFIG_PATH_ENV_VAR, &path);
+
+        let mut app = test_app();
+        assert!(!app.state.sidebar_collapsed);
+
+        std::fs::write(&path, "[ui]\nsidebar_start_collapsed = true\n").unwrap();
+        let report = app.reload_config();
+        assert_eq!(report.status, crate::config::ConfigReloadStatus::Applied);
+        assert!(!app.state.sidebar_collapsed);
+
+        std::env::remove_var(crate::config::CONFIG_PATH_ENV_VAR);
+        let _ = std::fs::remove_dir_all(path.parent().unwrap());
+    }
+
+    #[test]
     fn reload_config_updates_sidebar_collapsed_mode() {
         let _guard = config_env_lock().lock().unwrap();
         let path = temp_config_path("reload-config-sidebar-collapsed-mode");
diff --git a/src/config/model.rs b/src/config/model.rs
index 60dd2471..b32dc8a9 100644
--- a/src/config/model.rs
+++ b/src/config/model.rs
@@ -780,6 +780,8 @@ pub struct UiConfig {
     pub sidebar_min_width: u16,
     /// Maximum sidebar width (columns) when expanded. Default: 36.
     pub sidebar_max_width: u16,
+    /// Start with the sidebar collapsed. Default: false.
+    pub sidebar_start_collapsed: bool,
     /// Collapsed sidebar presentation. Default: compact.
     pub sidebar_collapsed_mode: SidebarCollapsedModeConfig,
     /// Terminal width at or below which Herdr uses the mobile single-column layout. Default: 64.
@@ -990,6 +992,7 @@ impl Default for UiConfig {
             sidebar_width: 26,
             sidebar_min_width: 18,
             sidebar_max_width: 36,
+            sidebar_start_collapsed: false,
             sidebar_collapsed_mode: SidebarCollapsedModeConfig::Compact,
             mobile_width_threshold: DEFAULT_MOBILE_WIDTH_THRESHOLD,
             mouse_capture: true,
@@ -1364,6 +1367,19 @@ mobile_width_threshold = 96
     }
 
     #[test]
+    fn sidebar_start_collapsed_defaults_off_and_parses_on() {
+        let default_config = Config::default();
+        assert!(!default_config.ui.sidebar_start_collapsed);
+
+        let toml = r#"
+[ui]
+sidebar_start_collapsed = true
+"#;
+        let config: Config = toml::from_str(toml).unwrap();
+        assert!(config.ui.sidebar_start_collapsed);
+    }
+
+    #[test]
     fn sidebar_collapsed_mode_defaults_compact_and_parses_hidden() {
         let default_config = Config::default();
         assert_eq!(
diff --git a/src/main.rs b/src/main.rs
index e1d9d87f..c48951c6 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -253,6 +253,9 @@ const DEFAULT_CONFIG: &str = r##"# herdr configuration
 # Maximum sidebar width when expanded (columns)
 # sidebar_max_width = 36
 
+# Start with the sidebar collapsed. Changes take effect on the next launch.
+# sidebar_start_collapsed = false
+
 # Collapsed sidebar presentation: "compact" keeps the narrow status rail, "hidden" uses zero width.
 # sidebar_collapsed_mode = "compact"