feat: Add persistent configuration and enumerate PipeWire audio devices

src/config.rs

@@ -0,0 +1,41 @@
+use serde::{Deserialize, Serialize};
+use std::fs;
+use std::path::PathBuf;
+
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+pub struct AppConfig {
+    pub input_device: String,
+    pub output_device: String,
+}
+
+impl AppConfig {
+    fn config_path() -> Option<PathBuf> {
+        dirs::config_dir().map(|mut p| {
+            p.push("peerspeak");
+            p.push("config.json");
+            p
+        })
+    }
+
+    pub fn load() -> Self {
+        if let Some(path) = Self::config_path() {
+            if let Ok(contents) = fs::read_to_string(&path) {
+                if let Ok(config) = serde_json::from_str(&contents) {
+                    return config;
+                }
+            }
+        }
+        Self::default()
+    }
+
+    pub fn save(&self) {
+        if let Some(path) = Self::config_path() {
+            if let Some(dir) = path.parent() {
+                let _ = fs::create_dir_all(dir);
+            }
+            if let Ok(json) = serde_json::to_string_pretty(self) {
+                let _ = fs::write(path, json);
+            }
+        }
+    }
+}