[feat](trx-app): support combined trx-rs.toml config file

Both trx-server and trx-client now look for a combined trx-rs.toml
with [trx-server] and [trx-client] section headers respectively,
falling back to per-binary config files as before.

Search order per tier: combined trx-rs.toml → flat per-binary file,
checked in CWD, ~/.config/trx-rs/, and /etc/trx-rs/.

--print-config now outputs the config under the appropriate section
header so the combined file can be generated directly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

src/trx-client/src/config.rs

@@ -411,6 +411,54 @@ impl ClientConfig {
 
         toml::to_string_pretty(&example).unwrap_or_default()
     }
+
+    /// Generate an example configuration wrapped under the `[trx-client]`
+    /// section header, suitable for use in a combined `trx-rs.toml` file.
+    pub fn example_combined_toml() -> String {
+        #[derive(serde::Serialize)]
+        struct Wrapper {
+            #[serde(rename = "trx-client")]
+            inner: ClientConfig,
+        }
+        let example = ClientConfig {
+            general: GeneralConfig {
+                callsign: Some("N0CALL".to_string()),
+                log_level: Some("info".to_string()),
+            },
+            remote: RemoteConfig {
+                url: Some("192.168.1.100:9000".to_string()),
+                rig_id: Some("hf".to_string()),
+                auth: RemoteAuthConfig {
+                    token: Some("my-token".to_string()),
+                },
+                poll_interval_ms: 750,
+            },
+            frontends: FrontendsConfig {
+                http: HttpFrontendConfig {
+                    enabled: true,
+                    listen: IpAddr::from([127, 0, 0, 1]),
+                    port: 8080,
+                    auth: HttpAuthConfig {
+                        enabled: false,
+                        rx_passphrase: Some("rx-passphrase-example".to_string()),
+                        control_passphrase: Some("control-passphrase-example".to_string()),
+                        tx_access_control_enabled: true,
+                        session_ttl_min: 480,
+                        cookie_secure: false,
+                        cookie_same_site: CookieSameSite::Lax,
+                    },
+                },
+                rigctl: RigctlFrontendConfig {
+                    enabled: false,
+                    listen: IpAddr::from([127, 0, 0, 1]),
+                    port: 4532,
+                },
+                http_json: HttpJsonFrontendConfig::default(),
+                audio: AudioClientConfig::default(),
+            },
+        };
+        toml::to_string_pretty(&Wrapper { inner: example }).unwrap_or_default()
+    }
 }
 
 fn validate_log_level(level: Option<&str>) -> Result<(), String> {
@@ -476,6 +524,10 @@ impl ConfigFile for ClientConfig {
         "client.toml"
     }
 
+    fn combined_key() -> Option<&'static str> {
+        Some("trx-client")
+    }
+
     fn default_search_paths() -> Vec<PathBuf> {
         let mut paths = Vec::new();
         paths.push(PathBuf::from("trx-client.toml"));

src/trx-client/src/main.rs

@@ -131,7 +131,7 @@ async fn async_init() -> DynResult<AppState> {
     let cli = Cli::parse();
 
     if cli.print_config {
-        println!("{}", ClientConfig::example_toml());
+        println!("{}", ClientConfig::example_combined_toml());
         std::process::exit(0);
     }