[style](trx-rs): fix clippy warnings for -D warnings CI

The CI lint job runs clippy with -D warnings, which surfaced a set of
existing warnings across decoders, the client, and the soapysdr backend.
Resolve them so the workspace is clean under the enforced lint level:

- collapsible_match / identity_op / needless_range_loop / same_item_push
  in trx-rds, trx-wspr, trx-vdes, trx-wefax, trx-aprs (mostly tests)
- field_reassign_with_default -> struct-update syntax in trx-client config
  tests
- assign_op_pattern, useless vec!, and test-module ordering picked up by
  cargo clippy --fix in trx-client and the soapysdr WFM tests

No behaviour changes; all affected crates' tests pass.

Assisted-By: Claude Code (claude-opus-4)
Claude-Session: https://claude.ai/code/session_01NFpGtGTWUEYXLwZeZs2RAV
Signed-off-by: Stan Grams <sjg@haxx.space>

src/trx-client/src/audio_client.rs

@@ -356,59 +356,6 @@ async fn run_single_rig_audio_client(
     }
 }
 
-#[cfg(test)]
-mod tests {
-    use super::{resolve_audio_addr, AudioConnectConfig};
-    use std::collections::HashMap;
-
-    #[test]
-    fn resolve_audio_addr_prefers_fixed_url() {
-        let mut rig_connect = HashMap::new();
-        rig_connect.insert(
-            "home-hf".to_string(),
-            AudioConnectConfig::fixed("audio.example.com:4700".to_string()),
-        );
-
-        let addr = resolve_audio_addr(
-            "home-hf",
-            Some(4531),
-            &rig_connect,
-            &AudioConnectConfig::from_host_port("control.example.com".to_string(), 4531),
-        );
-        assert_eq!(addr, "audio.example.com:4700");
-    }
-
-    #[test]
-    fn resolve_audio_addr_uses_advertised_port_with_remote_host() {
-        let mut rig_connect = HashMap::new();
-        rig_connect.insert(
-            "home-hf".to_string(),
-            AudioConnectConfig::from_host_port("control.example.com".to_string(), 4531),
-        );
-
-        let addr = resolve_audio_addr(
-            "home-hf",
-            Some(4600),
-            &rig_connect,
-            &AudioConnectConfig::from_host_port("fallback.example.com".to_string(), 4531),
-        );
-        assert_eq!(addr, "control.example.com:4600");
-    }
-
-    #[test]
-    fn resolve_audio_addr_falls_back_to_default_port() {
-        let rig_connect = HashMap::new();
-
-        let addr = resolve_audio_addr(
-            "home-hf",
-            None,
-            &rig_connect,
-            &AudioConnectConfig::from_host_port("fallback.example.com".to_string(), 4531),
-        );
-        assert_eq!(addr, "fallback.example.com:4531");
-    }
-}
-
 /// Handle a single TCP connection for one rig.  Similar to `handle_audio_connection`
 /// but publishes to per-rig channels directly and mirrors to global when selected.
 #[allow(clippy::too_many_arguments)]
@@ -767,3 +714,56 @@ async fn handle_single_rig_connection(
 
     Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::{resolve_audio_addr, AudioConnectConfig};
+    use std::collections::HashMap;
+
+    #[test]
+    fn resolve_audio_addr_prefers_fixed_url() {
+        let mut rig_connect = HashMap::new();
+        rig_connect.insert(
+            "home-hf".to_string(),
+            AudioConnectConfig::fixed("audio.example.com:4700".to_string()),
+        );
+
+        let addr = resolve_audio_addr(
+            "home-hf",
+            Some(4531),
+            &rig_connect,
+            &AudioConnectConfig::from_host_port("control.example.com".to_string(), 4531),
+        );
+        assert_eq!(addr, "audio.example.com:4700");
+    }
+
+    #[test]
+    fn resolve_audio_addr_uses_advertised_port_with_remote_host() {
+        let mut rig_connect = HashMap::new();
+        rig_connect.insert(
+            "home-hf".to_string(),
+            AudioConnectConfig::from_host_port("control.example.com".to_string(), 4531),
+        );
+
+        let addr = resolve_audio_addr(
+            "home-hf",
+            Some(4600),
+            &rig_connect,
+            &AudioConnectConfig::from_host_port("fallback.example.com".to_string(), 4531),
+        );
+        assert_eq!(addr, "control.example.com:4600");
+    }
+
+    #[test]
+    fn resolve_audio_addr_falls_back_to_default_port() {
+        let rig_connect = HashMap::new();
+
+        let addr = resolve_audio_addr(
+            "home-hf",
+            None,
+            &rig_connect,
+            &AudioConnectConfig::from_host_port("fallback.example.com".to_string(), 4531),
+        );
+        assert_eq!(addr, "fallback.example.com:4531");
+    }
+}

src/trx-client/src/config.rs

@@ -1110,36 +1110,40 @@ url = "remote.example.com:4530"
 
     #[test]
     fn test_validate_rejects_duplicate_remote_names() {
-        let mut config = ClientConfig::default();
-        config.remotes = vec![
-            RemoteEntry {
-                name: "dup".to_string(),
-                url: "a:4530".to_string(),
-                rig_id: None,
-                auth: RemoteAuthConfig::default(),
-                poll_interval_ms: 750,
-            },
-            RemoteEntry {
-                name: "dup".to_string(),
-                url: "b:4530".to_string(),
-                rig_id: None,
-                auth: RemoteAuthConfig::default(),
-                poll_interval_ms: 750,
-            },
-        ];
+        let config = ClientConfig {
+            remotes: vec![
+                RemoteEntry {
+                    name: "dup".to_string(),
+                    url: "a:4530".to_string(),
+                    rig_id: None,
+                    auth: RemoteAuthConfig::default(),
+                    poll_interval_ms: 750,
+                },
+                RemoteEntry {
+                    name: "dup".to_string(),
+                    url: "b:4530".to_string(),
+                    rig_id: None,
+                    auth: RemoteAuthConfig::default(),
+                    poll_interval_ms: 750,
+                },
+            ],
+            ..Default::default()
+        };
         assert!(config.validate().unwrap_err().contains("duplicate name"));
     }
 
     #[test]
     fn test_validate_rejects_empty_remote_name() {
-        let mut config = ClientConfig::default();
-        config.remotes = vec![RemoteEntry {
-            name: "".to_string(),
-            url: "a:4530".to_string(),
-            rig_id: None,
-            auth: RemoteAuthConfig::default(),
-            poll_interval_ms: 750,
-        }];
+        let config = ClientConfig {
+            remotes: vec![RemoteEntry {
+                name: "".to_string(),
+                url: "a:4530".to_string(),
+                rig_id: None,
+                auth: RemoteAuthConfig::default(),
+                poll_interval_ms: 750,
+            }],
+            ..Default::default()
+        };
         assert!(config
             .validate()
             .unwrap_err()
@@ -1148,14 +1152,16 @@ url = "remote.example.com:4530"
 
     #[test]
     fn test_validate_rejects_empty_remote_url() {
-        let mut config = ClientConfig::default();
-        config.remotes = vec![RemoteEntry {
-            name: "hf".to_string(),
-            url: "  ".to_string(),
-            rig_id: None,
-            auth: RemoteAuthConfig::default(),
-            poll_interval_ms: 750,
-        }];
+        let config = ClientConfig {
+            remotes: vec![RemoteEntry {
+                name: "hf".to_string(),
+                url: "  ".to_string(),
+                rig_id: None,
+                auth: RemoteAuthConfig::default(),
+                poll_interval_ms: 750,
+            }],
+            ..Default::default()
+        };
         assert!(config
             .validate()
             .unwrap_err()
@@ -1164,14 +1170,16 @@ url = "remote.example.com:4530"
 
     #[test]
     fn test_validate_rejects_zero_remote_poll_interval() {
-        let mut config = ClientConfig::default();
-        config.remotes = vec![RemoteEntry {
-            name: "hf".to_string(),
-            url: "a:4530".to_string(),
-            rig_id: None,
-            auth: RemoteAuthConfig::default(),
-            poll_interval_ms: 0,
-        }];
+        let config = ClientConfig {
+            remotes: vec![RemoteEntry {
+                name: "hf".to_string(),
+                url: "a:4530".to_string(),
+                rig_id: None,
+                auth: RemoteAuthConfig::default(),
+                poll_interval_ms: 0,
+            }],
+            ..Default::default()
+        };
         assert!(config
             .validate()
             .unwrap_err()

src/trx-client/src/remote_client.rs

@@ -1678,7 +1678,7 @@ mod tests {
     #[test]
     fn global_target_for_snapshot_skips_other_server_selection() {
         let snapshot = sample_snapshot();
-        let rigs = vec![RigEntry {
+        let rigs = [RigEntry {
             rig_id: "hf".to_string(),
             display_name: Some("Gdansk HF".to_string()),
             state: snapshot,