Keep a test's doc comment attached to its test

Adding the test_auth helper put it between
`/// The URL shape confirmed from a real H2C's ipcam block.` and the test
that comment describes, so the comment documented the helper instead.
Clippy's empty_line_after_doc_comments caught it. Also takes clippy's
from_ref over a clone in the new render-stability test.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/camera.rs

@@ -379,14 +379,14 @@ mod tests {
         ))
     }
 
-    /// The URL shape confirmed from a real H2C's `ipcam` block.
-
     /// A fixed credential, so the byte-identical assertions below stay
     /// meaningful. A real one is 32 random bytes and would make every
     /// rendered config differ from every other.
     fn test_auth() -> ApiAuth {
         ApiAuth { username: "continuum".into(), password: "test-password".into() }
     }
+
+    /// The URL shape confirmed from a real H2C's `ipcam` block.
     #[test]
     fn a_reported_rtsps_url_gets_the_printer_credentials_spliced_in() {
         let source = source_for(&printer("h2c"), Some("rtsps://192.168.0.21:322/streaming/live/1"))
@@ -506,7 +506,7 @@ mod tests {
     fn the_same_fleet_and_credential_render_identically() {
         let source = CameraSource { stream_name: "h2c".into(), url: "rtsps://x".into() };
         assert_eq!(
-            render_config(":1984", &[source.clone()], &test_auth()),
+            render_config(":1984", std::slice::from_ref(&source), &test_auth()),
             render_config(":1984", &[source], &test_auth()),
         );
     }