feat: dark/light theme toggle at runtime

src/ui/app.rs

@@ -9,7 +9,7 @@ use crate::db::{
     ConnectionConfig, ConnectionManager, DatabaseInfo, QueryResult, SchemaInfo, SslMode, TableInfo,
 };
 use crate::editor::{HistoryEntry, QueryHistory, TextBuffer};
-use crate::ui::Theme;
+use crate::ui::{Theme, ThemeName};
 
 pub const SPINNER_FRAMES: &[char] = &['⠋', '⠙', '⠹', '⠸', '⠼', '⠴', '⠦', '⠧', '⠇', '⠏'];
 
@@ -198,8 +198,13 @@ impl App {
             initial_config.password.len(),
         ];
 
+        let theme = match Self::load_theme_preference() {
+            ThemeName::Dark => Theme::dark(),
+            ThemeName::Light => Theme::light(),
+        };
+
         Self {
-            theme: Theme::dark(),
+            theme,
             focus: Focus::ConnectionDialog,
             should_quit: false,
 
@@ -298,9 +303,46 @@ impl App {
         }
     }
 
+    pub fn toggle_theme(&mut self) {
+        let new_name = self.theme.name.toggle();
+        self.theme = match new_name {
+            ThemeName::Dark => Theme::dark(),
+            ThemeName::Light => Theme::light(),
+        };
+        Self::save_theme_preference(new_name);
+    }
+
+    fn save_theme_preference(theme_name: ThemeName) {
+        if let Some(config_dir) = dirs::config_dir() {
+            let pgrsql_dir = config_dir.join("pgrsql");
+            let _ = std::fs::create_dir_all(&pgrsql_dir);
+            let _ = std::fs::write(pgrsql_dir.join("theme"), theme_name.as_str());
+        }
+    }
+
+    fn load_theme_preference() -> ThemeName {
+        if let Some(config_dir) = dirs::config_dir() {
+            let path = config_dir.join("pgrsql").join("theme");
+            if let Ok(content) = std::fs::read_to_string(path) {
+                return match content.trim() {
+                    "light" => ThemeName::Light,
+                    _ => ThemeName::Dark,
+                };
+            }
+        }
+        ThemeName::Dark
+    }
+
     pub async fn handle_input(&mut self, key: KeyEvent) -> Result<()> {
         // Global shortcuts
         match (key.code, key.modifiers) {
+            // Ctrl+Shift+T: Toggle theme (works in all contexts except connection dialog text input)
+            // Note: most terminals report Ctrl+Shift+T as Char('T') with only CONTROL;
+            // the SHIFT modifier is implicit in the uppercase letter.
+            (KeyCode::Char('T'), m) if m.contains(KeyModifiers::CONTROL) => {
+                self.toggle_theme();
+                return Ok(());
+            }
             (KeyCode::Char('?'), _) if self.focus != Focus::Editor => {
                 self.show_help = !self.show_help;
                 if self.show_help {

src/ui/components.rs

@@ -633,8 +633,12 @@ fn draw_status_bar(frame: &mut Frame, app: &App, area: Rect) {
         Style::default().fg(theme.text_muted).bg(theme.bg_secondary)
     };
 
-    // Right section: help hints
-    let right_text = "? Help | Ctrl+Q/D Quit ";
+    // Right section: theme indicator + help hints
+    let theme_indicator = match app.theme.name {
+        crate::ui::ThemeName::Dark => "Dark",
+        crate::ui::ThemeName::Light => "Light",
+    };
+    let right_text = format!("{} | ? Help | Ctrl+Q/D Quit ", theme_indicator);
 
     // Calculate padding
     let left_len = left_text.len() as u16;
@@ -945,6 +949,7 @@ fn draw_help_overlay(frame: &mut Frame, app: &App) {
         " GLOBAL",
         "   Ctrl+Q/D       Quit",
         "   Ctrl+C         Connect dialog",
+        "   Ctrl+Shift+T   Toggle theme",
         "   ?              Toggle help",
         "",
         " NAVIGATION",

src/ui/theme.rs

@@ -1,7 +1,14 @@
 use ratatui::style::{Color, Modifier, Style};
 
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum ThemeName {
+    Dark,
+    Light,
+}
+
 #[allow(dead_code)]
 pub struct Theme {
+    pub name: ThemeName,
     // Background colors
     pub bg_primary: Color,
     pub bg_secondary: Color,
@@ -43,10 +50,27 @@ impl Default for Theme {
     }
 }
 
+impl ThemeName {
+    pub fn toggle(self) -> Self {
+        match self {
+            ThemeName::Dark => ThemeName::Light,
+            ThemeName::Light => ThemeName::Dark,
+        }
+    }
+
+    pub fn as_str(&self) -> &'static str {
+        match self {
+            ThemeName::Dark => "dark",
+            ThemeName::Light => "light",
+        }
+    }
+}
+
 #[allow(dead_code)]
 impl Theme {
     pub fn dark() -> Self {
         Self {
+            name: ThemeName::Dark,
             // Background colors - dark blue-gray palette
             bg_primary: Color::Rgb(24, 26, 33),
             bg_secondary: Color::Rgb(30, 33, 43),
@@ -85,6 +109,7 @@ impl Theme {
 
     pub fn light() -> Self {
         Self {
+            name: ThemeName::Light,
             bg_primary: Color::Rgb(250, 250, 252),
             bg_secondary: Color::Rgb(240, 240, 245),
             bg_tertiary: Color::Rgb(230, 230, 238),