feat: add milestone 6 CLI polish

Add shell completion generation, improve first-run device messaging,
and include HTTP endpoint details in daemon startup output.

src/daemon/config.rs

@@ -9,7 +9,7 @@ use serde::{Deserialize, Serialize};
 use tokio::fs;
 
 /// The complete daemon configuration loaded from TOML.
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, Default)]
 #[serde(default)]
 pub struct TvctlConfig {
     /// Runtime daemon settings.
@@ -24,18 +24,6 @@ pub struct TvctlConfig {
     pub dev: DevConfig,
 }
 
-impl Default for TvctlConfig {
-    fn default() -> Self {
-        Self {
-            daemon: DaemonConfig::default(),
-            discovery: DiscoveryConfig::default(),
-            devices: DeviceConfig::default(),
-            remote: RemoteConfig::default(),
-            dev: DevConfig::default(),
-        }
-    }
-}
-
 impl TvctlConfig {
     /// Load configuration from the default XDG path or return defaults when absent.
     pub async fn load() -> anyhow::Result<Self> {