feat: --version flag with git hash + test script kill fix

wzp-relay --version prints "wzp-relay <short-git-hash>".
Build hash also logged on startup: version=abc1234.
Enables verifying deployed relay matches expected build.

Also fixed federation-test.sh: use kill -INT (not SIGTERM) so
clients save recordings before exit. Added save delay.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/wzp-relay/build.rs

@@ -0,0 +1,18 @@
+use std::process::Command;
+
+fn main() {
+    // Get git hash at build time
+    let output = Command::new("git")
+        .args(["rev-parse", "--short", "HEAD"])
+        .output();
+
+    let hash = match output {
+        Ok(o) if o.status.success() => {
+            String::from_utf8_lossy(&o.stdout).trim().to_string()
+        }
+        _ => "unknown".to_string(),
+    };
+
+    println!("cargo:rustc-env=WZP_BUILD_HASH={hash}");
+    println!("cargo:rerun-if-changed=.git/HEAD");
+}

crates/wzp-relay/src/main.rs

@@ -135,6 +135,10 @@ fn parse_args() -> CliResult {
                     args.get(i).expect("--debug-tap requires a room name (or '*' for all)").to_string(),
                 );
             }
+            "--version" | "-V" => {
+                println!("wzp-relay {}", env!("WZP_BUILD_HASH"));
+                std::process::exit(0);
+            }
             "--mesh-status" => {
                 // Print mesh table from a fresh registry and exit.
                 // In practice this is useful after the relay has been running;
@@ -257,10 +261,14 @@ fn detect_public_ip() -> Option<String> {
     None
 }
 
+/// Build-time git hash, set by build.rs or env.
+const BUILD_GIT_HASH: &str = env!("WZP_BUILD_HASH");
+
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
     let CliResult { mut config, identity_path, config_file, config_needs_create } = parse_args();
     tracing_subscriber::fmt().init();
+    info!(version = BUILD_GIT_HASH, "wzp-relay build");
     rustls::crypto::ring::default_provider()
         .install_default()
         .expect("failed to install rustls crypto provider");

scripts/federation-test.sh

@@ -112,7 +112,7 @@ PIDS+=($!); sleep 2
 RUST_LOG=error $CLIENT --room $ROOM --seed $SEED_A --send-tone $DURATION "$RELAY1" &
 PIDS+=($!); sleep $((DURATION + 3))
 
-kill ${PIDS[-1]} ${PIDS[-2]} 2>/dev/null; wait ${PIDS[-1]} ${PIDS[-2]} 2>/dev/null || true
+kill -INT ${PIDS[-2]} 2>/dev/null; sleep 3; kill -INT ${PIDS[-1]} 2>/dev/null; wait ${PIDS[-1]} ${PIDS[-2]} 2>/dev/null || true
 PIDS=("${PIDS[@]:0:${#PIDS[@]}-2}")
 
 analyze "$RESULTS/t1_b.raw" "Relay1→Relay2 audio"
@@ -129,7 +129,7 @@ PIDS+=($!); sleep 2
 RUST_LOG=error $CLIENT --room $ROOM --seed $SEED_B --send-tone $DURATION "$RELAY2" &
 PIDS+=($!); sleep $((DURATION + 3))
 
-kill ${PIDS[-1]} ${PIDS[-2]} 2>/dev/null; wait ${PIDS[-1]} ${PIDS[-2]} 2>/dev/null || true
+kill -INT ${PIDS[-2]} 2>/dev/null; sleep 3; kill -INT ${PIDS[-1]} 2>/dev/null; wait ${PIDS[-1]} ${PIDS[-2]} 2>/dev/null || true
 PIDS=("${PIDS[@]:0:${#PIDS[@]}-2}")
 
 analyze "$RESULTS/t2_a.raw" "Relay2→Relay1 audio"
@@ -146,7 +146,7 @@ PIDS+=($!); sleep 2
 RUST_LOG=error $CLIENT --room $ROOM --seed $SEED_A --send-tone $DURATION "$RELAY1" &
 PIDS+=($!); sleep $((DURATION + 3))
 
-kill ${PIDS[-1]} ${PIDS[-2]} 2>/dev/null; wait ${PIDS[-1]} ${PIDS[-2]} 2>/dev/null || true
+kill -INT ${PIDS[-2]} 2>/dev/null; sleep 3; kill -INT ${PIDS[-1]} 2>/dev/null; wait ${PIDS[-1]} ${PIDS[-2]} 2>/dev/null || true
 PIDS=("${PIDS[@]:0:${#PIDS[@]}-2}")
 
 analyze "$RESULTS/t3_c.raw" "Relay1→Relay3 (via Relay2) audio"
@@ -163,7 +163,7 @@ PIDS+=($!); sleep 2
 RUST_LOG=error $CLIENT --room $ROOM --seed $SEED_A --send-file "$AUDIO" "$RELAY1" &
 PIDS+=($!); sleep 20  # file is 60s but we only wait 20
 
-kill ${PIDS[-1]} ${PIDS[-2]} 2>/dev/null; wait ${PIDS[-1]} ${PIDS[-2]} 2>/dev/null || true
+kill -INT ${PIDS[-2]} 2>/dev/null; sleep 3; kill -INT ${PIDS[-1]} 2>/dev/null; wait ${PIDS[-1]} ${PIDS[-2]} 2>/dev/null || true
 PIDS=("${PIDS[@]:0:${#PIDS[@]}-2}")
 
 analyze "$RESULTS/t4_b.raw" "File playback Relay1→Relay2"
@@ -193,7 +193,7 @@ RUST_LOG=error $CLIENT --room $ROOM --seed $SEED_B --record "$RESULTS/t5_b_rejoi
 B_PID=$!; PIDS+=($B_PID)
 sleep 8
 kill -INT $B_PID 2>/dev/null; wait $B_PID 2>/dev/null || true
-kill $A_PID 2>/dev/null; wait $A_PID 2>/dev/null || true
+kill -INT $A_PID 2>/dev/null; wait $A_PID 2>/dev/null || true
 
 analyze "$RESULTS/t5_b_first.raw" "B first join (before disconnect)"
 analyze "$RESULTS/t5_b_rejoin.raw" "B rejoin (after disconnect)"
@@ -213,7 +213,7 @@ PIDS+=($!); sleep $((DURATION + 3))
 
 # Kill all 3
 for i in 1 2 3; do
-    kill ${PIDS[-$i]} 2>/dev/null || true
+    kill -INT ${PIDS[-$i]} 2>/dev/null || true
 done
 wait 2>/dev/null || true
 PIDS=()