chore(clippy): appease 1.97 lints — derive Default, collapse ifs, drop needless borrow

Pre-existing, surfaced by the toolchain bump (rust-version is 1.95; the
sandbox gates with stable 1.97). All four are cargo clippy --fix output
with the mechanical-collapse indentation hand-tidied to house style;
the parser change is semantics-preserving (a non-100-continue Expect
value now falls to the _ arm instead of an empty if — headers.append
still runs after the match either way). No fmt pass: rustfmt would
clobber the aligned-assignment style, so only the touched lines moved.

examples/ws_chat.rs

@@ -92,7 +92,7 @@ impl WsHandler for ChatHandler {
         // subscribed as.
         let _ = self
             .bus()
-            .broadcast_from(smarm::self_pid(), &self.topic(), text);
+            .broadcast_from(smarm::self_pid(), self.topic(), text);
     }
 
     fn on_close(&mut self, _code: Option<u16>, _reason: &str) {

src/conn.rs

@@ -158,7 +158,9 @@ impl Body {
 // Empty `Vec`s are skipped by the pump (a zero-length chunk would
 // terminate chunked framing early), so they are safe to send but useless.
 
+#[derive(Default)]
 pub enum RespBody {
+    #[default]
     Empty,
     Bytes(Vec<u8>),
     Stream(StreamBody),
@@ -217,10 +219,6 @@ impl RespBody {
     }
 }
 
-impl Default for RespBody {
-    fn default() -> Self { RespBody::Empty }
-}
-
 // ---------------------------------------------------------------------------
 // Params — path parameters extracted by the router.
 // ---------------------------------------------------------------------------

src/conn_actor.rs

@@ -157,10 +157,10 @@ pub fn run_connection(
         // If client sent `Expect: 100-continue`, emit it before reading the
         // body. RFC 7231 §5.1.1. We don't gate on app logic here; v1 always
         // accepts.
-        if parsed.expect_100 {
-            if write_all(raw, b"HTTP/1.1 100 Continue\r\n\r\n", Instant::now() + limits.write_timeout).is_err() {
-                return;
-            }
+        if parsed.expect_100
+            && write_all(raw, b"HTTP/1.1 100 Continue\r\n\r\n", Instant::now() + limits.write_timeout).is_err()
+        {
+            return;
         }
 
         // `consumed_past_head`: how many RAW bytes of `buf` past the head

src/parser.rs

@@ -123,10 +123,8 @@ pub fn parse_head(buf: &[u8], max_headers: usize) -> Result<ParsedHead, ParseErr
             "connection" => {
                 connection_hdr = Some(value.to_ascii_lowercase());
             }
-            "expect" => {
-                if value.eq_ignore_ascii_case("100-continue") {
-                    expect_100 = true;
-                }
+            "expect" if value.eq_ignore_ascii_case("100-continue") => {
+                expect_100 = true;
             }
             _ => {}
         }