fix: keep sidebar width stable and persist user resize

5 files changed, 38 insertions, 51 deletions

diff --git a/src/app/input.rs b/src/app/input.rs
index 6af7cf0e..64731bf3 100644
--- a/src/app/input.rs
+++ b/src/app/input.rs
@@ -318,7 +318,8 @@ impl App {
             self.last_sidebar_divider_click = Some(now);
 
             if is_double_click {
-                self.state.sidebar_width_auto = true;
+                self.state.sidebar_width = self.state.default_sidebar_width;
+                self.state.sidebar_width_auto = false;
                 self.state.drag = None;
                 return;
             }
@@ -1918,7 +1919,6 @@ impl AppState {
                     self.drag = Some(DragState {
                         target: DragTarget::SidebarDivider,
                     });
-                    self.sidebar_width_auto = false;
                     self.set_manual_sidebar_width(mouse.column);
                     return None;
                 }
@@ -2154,7 +2154,6 @@ impl AppState {
                             }
                         }
                         DragTarget::SidebarDivider => {
-                            self.sidebar_width_auto = false;
                             self.set_manual_sidebar_width(mouse.column);
                         }
                         DragTarget::ReleaseNotesScrollbar { .. }
@@ -3734,21 +3733,20 @@ mod tests {
         app.handle_mouse(mouse(MouseEventKind::Down(MouseButton::Left), 25, 5));
         app.handle_mouse(mouse(MouseEventKind::Drag(MouseButton::Left), 30, 5));
 
-        assert!(!app.state.sidebar_width_auto);
         assert_eq!(app.state.sidebar_width, 31);
     }
 
     #[test]
-    fn double_clicking_sidebar_divider_resets_auto_width() {
+    fn double_clicking_sidebar_divider_resets_default_width() {
         let mut app = app_for_mouse_test();
-        app.state.sidebar_width_auto = false;
+        app.state.default_sidebar_width = 26;
         app.state.sidebar_width = 30;
 
         app.handle_mouse(mouse(MouseEventKind::Down(MouseButton::Left), 25, 5));
         app.handle_mouse(mouse(MouseEventKind::Up(MouseButton::Left), 25, 5));
         app.handle_mouse(mouse(MouseEventKind::Down(MouseButton::Left), 25, 5));
 
-        assert!(app.state.sidebar_width_auto);
+        assert_eq!(app.state.sidebar_width, 26);
         assert!(app.state.drag.is_none());
     }
 
diff --git a/src/app/mod.rs b/src/app/mod.rs
index f06bbb19..6d677b0c 100644
--- a/src/app/mod.rs
+++ b/src/app/mod.rs
@@ -157,12 +157,13 @@ impl App {
         let render_dirty = Arc::new(AtomicBool::new(false));
 
         // Try to restore previous session
-        let (workspaces, active, selected, agent_panel_scope) = if no_session {
+        let (workspaces, active, selected, agent_panel_scope, sidebar_width) = if no_session {
             (
                 Vec::new(),
                 None,
                 0,
                 state::AgentPanelScope::CurrentWorkspace,
+                config.ui.sidebar_width,
             )
         } else if let Some(snap) = crate::persist::load() {
             let ws = crate::persist::restore(
@@ -175,12 +176,24 @@ impl App {
             );
             if ws.is_empty() {
                 info!("session file found but no workspaces restored");
-                (Vec::new(), None, 0, snap.agent_panel_scope)
+                (
+                    Vec::new(),
+                    None,
+                    0,
+                    snap.agent_panel_scope,
+                    snap.sidebar_width.unwrap_or(config.ui.sidebar_width),
+                )
             } else {
                 info!(count = ws.len(), "session restored");
                 let active = snap.active.filter(|&i| i < ws.len());
                 let selected = snap.selected.min(ws.len().saturating_sub(1));
-                (ws, active, selected, snap.agent_panel_scope)
+                (
+                    ws,
+                    active,
+                    selected,
+                    snap.agent_panel_scope,
+                    snap.sidebar_width.unwrap_or(config.ui.sidebar_width),
+                )
             }
         } else {
             (
@@ -188,6 +201,7 @@ impl App {
                 None,
                 0,
                 state::AgentPanelScope::CurrentWorkspace,
+                config.ui.sidebar_width,
             )
         };
 
@@ -247,8 +261,9 @@ impl App {
             toast: None,
             prefix_code,
             prefix_mods,
-            sidebar_width: config.ui.sidebar_width,
-            sidebar_width_auto: true,
+            default_sidebar_width: config.ui.sidebar_width,
+            sidebar_width,
+            sidebar_width_auto: false,
             sidebar_collapsed: false,
             agent_panel_scope,
             confirm_close: config.ui.confirm_close,
@@ -434,6 +449,7 @@ impl App {
                 self.state.active,
                 self.state.selected,
                 self.state.agent_panel_scope,
+                self.state.sidebar_width,
             );
             crate::persist::save(&snap);
         }
diff --git a/src/app/state.rs b/src/app/state.rs
index 60cb0511..84920131 100644
--- a/src/app/state.rs
+++ b/src/app/state.rs
@@ -595,6 +595,7 @@ pub struct AppState {
     // Config
     pub prefix_code: KeyCode,
     pub prefix_mods: KeyModifiers,
+    pub default_sidebar_width: u16,
     pub sidebar_width: u16,
     pub sidebar_width_auto: bool,
     pub sidebar_collapsed: bool,
@@ -703,8 +704,9 @@ impl AppState {
             toast: None,
             prefix_code: KeyCode::Char('b'),
             prefix_mods: KeyModifiers::CONTROL,
+            default_sidebar_width: 26,
             sidebar_width: 26,
-            sidebar_width_auto: true,
+            sidebar_width_auto: false,
             sidebar_collapsed: false,
             agent_panel_scope: AgentPanelScope::CurrentWorkspace,
             confirm_close: true,
diff --git a/src/persist.rs b/src/persist.rs
index 72ac9bef..292af92d 100644
--- a/src/persist.rs
+++ b/src/persist.rs
@@ -32,6 +32,8 @@ pub struct SessionSnapshot {
     pub selected: usize,
     #[serde(default)]
     pub agent_panel_scope: crate::app::state::AgentPanelScope,
+    #[serde(default)]
+    pub sidebar_width: Option<u16>,
 }
 
 #[derive(Serialize)]
@@ -218,6 +220,7 @@ pub fn capture(
     active: Option<usize>,
     selected: usize,
     agent_panel_scope: crate::app::state::AgentPanelScope,
+    sidebar_width: u16,
 ) -> SessionSnapshot {
     SessionSnapshot {
         version: SNAPSHOT_VERSION,
@@ -225,6 +228,7 @@ pub fn capture(
         active,
         selected,
         agent_panel_scope,
+        sidebar_width: Some(sidebar_width),
     }
 }
 
@@ -561,11 +565,13 @@ mod tests {
             active: None,
             selected: 0,
             agent_panel_scope: crate::app::state::AgentPanelScope::CurrentWorkspace,
+            sidebar_width: Some(26),
         };
         let json = serde_json::to_string(&snap).unwrap();
         let restored: SessionSnapshot = serde_json::from_str(&json).unwrap();
         assert!(restored.workspaces.is_empty());
         assert_eq!(restored.active, None);
+        assert_eq!(restored.sidebar_width, Some(26));
     }
 
     #[test]
@@ -630,6 +636,7 @@ mod tests {
             active: Some(0),
             selected: 0,
             agent_panel_scope: crate::app::state::AgentPanelScope::CurrentWorkspace,
+            sidebar_width: Some(26),
             version: SNAPSHOT_VERSION,
         };
 
@@ -652,6 +659,7 @@ mod tests {
             restored.agent_panel_scope,
             crate::app::state::AgentPanelScope::CurrentWorkspace
         );
+        assert_eq!(restored.sidebar_width, Some(26));
     }
 
     #[test]
@@ -670,6 +678,7 @@ mod tests {
             restored.agent_panel_scope,
             crate::app::state::AgentPanelScope::CurrentWorkspace
         );
+        assert_eq!(restored.sidebar_width, None);
     }
 
     #[test]
diff --git a/src/ui.rs b/src/ui.rs
index 247199b1..3783dd5c 100644
--- a/src/ui.rs
+++ b/src/ui.rs
@@ -208,8 +208,6 @@ fn format_agent_panel_primary_label(entry: &AgentPanelEntry, max_width: usize) -
 pub fn compute_view(app: &mut AppState, area: Rect) {
     let sidebar_w = if app.sidebar_collapsed {
         COLLAPSED_WIDTH
-    } else if app.sidebar_width_auto {
-        compute_sidebar_width(app)
     } else {
         app.sidebar_width
             .clamp(MIN_SIDEBAR_WIDTH, MAX_SIDEBAR_WIDTH)
@@ -588,42 +586,6 @@ fn compute_pane_infos(app: &AppState, area: Rect) -> Vec<PaneInfo> {
 }
 
 /// Auto-scale sidebar width based on workspace identity + agent summary.
-fn compute_sidebar_width(app: &AppState) -> u16 {
-    if app.workspaces.is_empty() {
-        return app
-            .sidebar_width
-            .clamp(MIN_SIDEBAR_WIDTH, MAX_SIDEBAR_WIDTH);
-    }
-    let max_workspace_line = app
-        .workspaces
-        .iter()
-        .enumerate()
-        .map(|(i, ws)| {
-            let name_len = ws.display_name().len();
-            let number_len = (i + 1).to_string().len();
-            // marker + number + space + name + spaces + aggregate dot
-            let line1 = 3 + number_len + name_len + 3;
-            // branch line: "  branch"
-            let line2 = ws.branch().map(|b| 3 + b.len()).unwrap_or(0);
-            line1.max(line2)
-        })
-        .max()
-        .unwrap_or(12);
-    let max_agent_line = app
-        .workspaces
-        .iter()
-        .flat_map(|ws| ws.pane_details().into_iter())
-        .map(|detail| {
-            let name_line = 3 + detail.label.len(); // " icon name"
-            let state_line = 2 + state_label(detail.state, detail.seen).len(); // "  state"
-            name_line.max(state_line)
-        })
-        .max()
-        .unwrap_or(0);
-    ((max_workspace_line.max(max_agent_line) as u16) + 2)
-        .clamp(MIN_SIDEBAR_WIDTH, MAX_SIDEBAR_WIDTH)
-}
-
 pub(crate) fn collapsed_sidebar_sections(area: Rect) -> (Rect, Option<u16>, Rect) {
     let content = Rect::new(area.x, area.y, area.width.saturating_sub(1), area.height);
     if content.width == 0 || content.height == 0 {