feat: add ecc2 runtime theme toggle

ecc2/src/config/mod.rs

@@ -40,7 +40,7 @@ pub struct Config {
     pub risk_thresholds: RiskThresholds,
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
 pub enum Theme {
     Dark,
     Light,

ecc2/src/tui/app.rs

@@ -50,6 +50,7 @@ pub async fn run(db: StateStore, cfg: Config) -> Result<()> {
                     (_, KeyCode::Char('m')) => dashboard.merge_selected_worktree().await,
                     (_, KeyCode::Char('M')) => dashboard.merge_ready_worktrees().await,
                     (_, KeyCode::Char('l')) => dashboard.cycle_pane_layout(),
+                    (_, KeyCode::Char('T')) => dashboard.toggle_theme(),
                     (_, KeyCode::Char('p')) => dashboard.toggle_auto_dispatch_policy(),
                     (_, KeyCode::Char('t')) => dashboard.toggle_auto_worktree_policy(),
                     (_, KeyCode::Char('w')) => dashboard.toggle_auto_merge_policy(),

ecc2/src/tui/dashboard.rs

@@ -9,7 +9,7 @@ use tokio::sync::broadcast;
 
 use super::widgets::{budget_state, format_currency, format_token_count, BudgetState, TokenMeter};
 use crate::comms;
-use crate::config::{Config, PaneLayout};
+use crate::config::{Config, PaneLayout, Theme};
 use crate::observability::ToolLogEntry;
 use crate::session::manager;
 use crate::session::output::{OutputEvent, OutputLine, SessionOutputStore, OUTPUT_BUFFER_LIMIT};
@@ -45,6 +45,14 @@ struct WorktreeDiffColumns {
     additions: String,
 }
 
+#[derive(Debug, Clone, Copy)]
+struct ThemePalette {
+    accent: Color,
+    row_highlight_bg: Color,
+    muted: Color,
+    help_border: Color,
+}
+
 pub struct Dashboard {
     db: StateStore,
     cfg: Config,
@@ -244,11 +252,13 @@ impl Dashboard {
             .filter(|session| session.state == SessionState::Running)
             .count();
         let total = self.sessions.len();
+        let palette = self.theme_palette();
 
         let title = format!(
-            " ECC 2.0 | {running} running / {total} total | {} {}% ",
+            " ECC 2.0 | {running} running / {total} total | {} {}% | {} ",
             self.layout_label(),
-            self.pane_size_percent
+            self.pane_size_percent,
+            self.theme_label()
         );
         let tabs = Tabs::new(
             self.visible_panes()
@@ -260,7 +270,7 @@ impl Dashboard {
         .select(self.selected_pane_index())
         .highlight_style(
             Style::default()
-                .fg(Color::Cyan)
+                .fg(palette.accent)
                 .add_modifier(Modifier::BOLD),
         );
 
@@ -332,7 +342,7 @@ impl Dashboard {
             .highlight_spacing(HighlightSpacing::Always)
             .row_highlight_style(
                 Style::default()
-                    .bg(Color::DarkGray)
+                    .bg(self.theme_palette().row_highlight_bg)
                     .add_modifier(Modifier::BOLD),
             );
 
@@ -530,8 +540,9 @@ impl Dashboard {
 
     fn render_status_bar(&self, frame: &mut Frame, area: Rect) {
         let text = format!(
-            " [n]ew session  [a]ssign  re[b]alance  global re[B]alance  dra[i]n inbox  [g]lobal dispatch  coordinate [G]lobal  [v]iew diff  conflict proto[c]ol  [m]erge  merge ready [M]  auto-worktree [t]  auto-merge [w]  toggle [p]olicy  [,/.] dispatch limit  [s]top  [u]resume  [x]cleanup  prune inactive [X]  [d]elete  [r]efresh  [Tab] switch pane  [j/k] scroll  [+/-] resize  [l]ayout {}  [?] help  [q]uit ",
+            " [n]ew session  [a]ssign  re[b]alance  global re[B]alance  dra[i]n inbox  [g]lobal dispatch  coordinate [G]lobal  [v]iew diff  conflict proto[c]ol  [m]erge  merge ready [M]  auto-worktree [t]  auto-merge [w]  toggle [p]olicy  [,/.] dispatch limit  [s]top  [u]resume  [x]cleanup  prune inactive [X]  [d]elete  [r]efresh  [Tab] switch pane  [j/k] scroll  [+/-] resize  [l]ayout {}  [T]heme {}  [?] help  [q]uit ",
-            self.layout_label()
+            self.layout_label(),
+            self.theme_label()
         );
         let text = if let Some(note) = self.operator_note.as_ref() {
             format!(" {} |{}", truncate_for_dashboard(note, 96), text)
@@ -559,7 +570,7 @@ impl Dashboard {
             .split(inner);
 
         frame.render_widget(
-            Paragraph::new(text).style(Style::default().fg(Color::DarkGray)),
+            Paragraph::new(text).style(Style::default().fg(self.theme_palette().muted)),
             chunks[0],
         );
         frame.render_widget(
@@ -586,6 +597,7 @@ impl Dashboard {
             "  m       Merge selected ready worktree into base and clean it up",
             "  M       Merge all ready inactive worktrees and clean them up",
             "  l       Cycle pane layout and persist it",
+            "  T       Toggle theme and persist it",
             "  t       Toggle default worktree creation for new sessions and delegated work",
             "  p       Toggle daemon auto-dispatch policy and persist config",
             "  w       Toggle daemon auto-merge for ready inactive worktrees",
@@ -610,7 +622,7 @@ impl Dashboard {
             Block::default()
                 .borders(Borders::ALL)
                 .title(" Help ")
-                .border_style(Style::default().fg(Color::Yellow)),
+                .border_style(Style::default().fg(self.theme_palette().help_border)),
         );
         frame.render_widget(paragraph, area);
     }
@@ -673,6 +685,34 @@ impl Dashboard {
         }
     }
 
+    pub fn toggle_theme(&mut self) {
+        let config_path = crate::config::Config::config_path();
+        self.toggle_theme_with_save(&config_path, |cfg| cfg.save());
+    }
+
+    fn toggle_theme_with_save<F>(&mut self, config_path: &std::path::Path, save: F)
+    where
+        F: FnOnce(&Config) -> anyhow::Result<()>,
+    {
+        let previous_theme = self.cfg.theme;
+        self.cfg.theme = match self.cfg.theme {
+            Theme::Dark => Theme::Light,
+            Theme::Light => Theme::Dark,
+        };
+
+        match save(&self.cfg) {
+            Ok(()) => self.set_operator_note(format!(
+                "theme set to {} | saved to {}",
+                self.theme_label(),
+                config_path.display()
+            )),
+            Err(error) => {
+                self.cfg.theme = previous_theme;
+                self.set_operator_note(format!("failed to persist theme: {error}"));
+            }
+        }
+    }
+
     pub fn increase_pane_size(&mut self) {
         self.pane_size_percent =
             (self.pane_size_percent + PANE_RESIZE_STEP_PERCENT).min(MAX_PANE_SIZE_PERCENT);
@@ -2371,7 +2411,7 @@ impl Dashboard {
 
     fn pane_border_style(&self, pane: Pane) -> Style {
         if self.selected_pane == pane {
-            Style::default().fg(Color::Cyan)
+            Style::default().fg(self.theme_palette().accent)
         } else {
             Style::default()
         }
@@ -2385,6 +2425,30 @@ impl Dashboard {
         }
     }
 
+    fn theme_label(&self) -> &'static str {
+        match self.cfg.theme {
+            Theme::Dark => "dark",
+            Theme::Light => "light",
+        }
+    }
+
+    fn theme_palette(&self) -> ThemePalette {
+        match self.cfg.theme {
+            Theme::Dark => ThemePalette {
+                accent: Color::Cyan,
+                row_highlight_bg: Color::DarkGray,
+                muted: Color::DarkGray,
+                help_border: Color::Yellow,
+            },
+            Theme::Light => ThemePalette {
+                accent: Color::Blue,
+                row_highlight_bg: Color::Gray,
+                muted: Color::Black,
+                help_border: Color::Blue,
+            },
+        }
+    }
+
     fn log_field<'a>(&self, value: &'a str) -> &'a str {
         let trimmed = value.trim();
         if trimmed.is_empty() {
@@ -4270,6 +4334,41 @@ diff --git a/src/next.rs b/src/next.rs
         let _ = std::fs::remove_dir_all(tempdir);
     }
 
+    #[test]
+    fn toggle_theme_persists_config() {
+        let mut dashboard = test_dashboard(Vec::new(), 0);
+        let tempdir = std::env::temp_dir().join(format!("ecc2-theme-policy-{}", Uuid::new_v4()));
+        std::fs::create_dir_all(&tempdir).unwrap();
+        let config_path = tempdir.join("ecc2.toml");
+
+        dashboard.toggle_theme_with_save(&config_path, |cfg| cfg.save_to_path(&config_path));
+
+        assert_eq!(dashboard.cfg.theme, Theme::Light);
+        let expected_note = format!("theme set to light | saved to {}", config_path.display());
+        assert_eq!(
+            dashboard.operator_note.as_deref(),
+            Some(expected_note.as_str())
+        );
+
+        let saved = std::fs::read_to_string(&config_path).unwrap();
+        let loaded: Config = toml::from_str(&saved).unwrap();
+        assert_eq!(loaded.theme, Theme::Light);
+        let _ = std::fs::remove_dir_all(tempdir);
+    }
+
+    #[test]
+    fn light_theme_uses_light_palette_accent() {
+        let mut dashboard = test_dashboard(Vec::new(), 0);
+        dashboard.cfg.theme = Theme::Light;
+        dashboard.selected_pane = Pane::Sessions;
+
+        assert_eq!(
+            dashboard.pane_border_style(Pane::Sessions),
+            Style::default().fg(Color::Blue)
+        );
+        assert_eq!(dashboard.theme_palette().row_highlight_bg, Color::Gray);
+    }
+
     fn test_dashboard(sessions: Vec<Session>, selected_session: usize) -> Dashboard {
         let selected_session = selected_session.min(sessions.len().saturating_sub(1));
         let cfg = Config::default();