feat: add configuration management and panel rendering

- Introduced a new `Config` struct for loading application configuration from a TOML file.
- Added support for keybindings and panel configurations, including status widgets.
- Implemented `PtyTerminal` for handling pseudo-terminal interactions.
- Created a rendering module to manage the display of application windows, panels, and dropdowns.
- Refactored the main application loop to utilize the new configuration and rendering logic.
- Removed legacy code related to event handling and rendering from `main.rs`.

dist/linux/panels/topbar.toml

@@ -0,0 +1,23 @@
+# Topbar – Linux
+
+[[item]]
+label = "Terminal"
+action = { type = "spawn_terminal" }
+
+[[item]]
+label = "Exit"
+action = { type = "exit" }
+
+# Klocka – uppdateras varje sekund
+[[status]]
+command = "date '+%H:%M:%S'"
+interval = 1
+width = 10
+align = "right"
+
+# Datum – uppdateras varje minut
+[[status]]
+command = "date '+%Y-%m-%d'"
+interval = 60
+width = 12
+align = "right"