Implement Kitty graphics protocol for background image rendering

- Added `kitty_gfx` module to handle loading, scaling, and displaying background images using the Kitty graphics protocol.
- Integrated background image handling into the main application loop, allowing dynamic updates based on configuration.
- Enhanced terminal rendering to support transparent backgrounds when a Kitty image is active.
- Updated IPC server to manage client connections and messages, including handling background image settings.
- Modified `PtyTerminal` to accept additional environment variables during shell spawning.
- Improved rendering logic to support popup dialogs and terminal background color customization.

src/config.rs

@@ -3,6 +3,16 @@ use std::fs;
 
 #[derive(Deserialize, Debug, Clone, Default)]
 pub struct Config {
+    /// Sökväg till bakgrundsbild (Kitty graphics protocol)
+    #[serde(default)]
+    pub background_image: Option<String>,
+    /// Bakgrundsfärg för virtuella terminaler. Om None → genomskinlig (Color::Reset).
+    /// Stödjer: "#RRGGBB", "N" (indexed 0-255), färgnamn.
+    #[serde(default)]
+    pub terminal_bg_color: Option<String>,
+    /// Standard-shell för nya terminaler. Om None → $SHELL eller /bin/bash.
+    #[serde(default)]
+    pub default_shell: Option<String>,
     #[serde(default, rename = "panel")]
     pub panels: Vec<PanelConfig>,
     #[serde(default, rename = "keybind")]
@@ -134,6 +144,24 @@ fn default_keybinds() -> Vec<KeybindConfig> {
     ]
 }
 
+fn default_panels() -> Vec<PanelConfig> {
+    vec![PanelConfig {
+        position: PanelPosition::Top,
+        items: vec![
+            MenuItem {
+                label: "Terminal".to_string(),
+                action: MenuAction::SpawnTerminal { shell: Some("/bin/bash".to_string()) },
+            },
+            MenuItem {
+                label: "Avsluta".to_string(),
+                action: MenuAction::Exit,
+            },
+        ],
+        status_widgets: vec![],
+        file: None,
+    }]
+}
+
 impl Config {
     pub fn load(path: &str) -> anyhow::Result<Config> {
         let content = fs::read_to_string(path)?;
@@ -157,12 +185,31 @@ impl Config {
             Err(e) => {
                 eprintln!("Varning: kunde inte ladda {}: {}", path, e);
                 Config {
+                    background_image: None,
+                    terminal_bg_color: None,
+                    default_shell: None,
+                    panels: default_panels(),
                     keybinds: default_keybinds(),
-                    ..Config::default()
                 }
             }
         }
     }
+
+    /// Uppdatera background_image i config-filen (TOML)
+    pub fn save_background(path: &str, image_path: Option<&str>) -> anyhow::Result<()> {
+        let content = fs::read_to_string(path).unwrap_or_default();
+        let mut doc: toml_edit::DocumentMut = content.parse().unwrap_or_default();
+        match image_path {
+            Some(p) => {
+                doc["background_image"] = toml_edit::value(p);
+            }
+            None => {
+                doc.remove("background_image");
+            }
+        }
+        fs::write(path, doc.to_string())?;
+        Ok(())
+    }
 }
 
 #[derive(Deserialize)]