Wait for the web admin process to actually die on shutdown

Complements the retry fix on the bind side: pkill only sends SIGTERM
and returns immediately, it doesn't wait for the process to exit and
release its socket. Under network_mode: host there's no Docker-
managed port mapping to tear down, so the next container's bind
attempt was racing however long this process actually took to die —
sometimes still holding the port when the next container started.

Poll for it to actually exit (up to 2s), falling back to SIGKILL if
it's still lingering, before proceeding with the rest of shutdown.
With a clean handoff here, the web admin's own bind-retry (previous
commit) should rarely even need to kick in.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015X1jRGHwrvovz2qkhKfDZi

vendor/easy-asterisk/docker/entrypoint.sh

@@ -464,7 +464,20 @@ fi
 # ── 11. Signal handling for clean shutdown ────────────────────
 cleanup() {
     log_info "Shutting down..."
-    pkill -f "easy-asterisk-webadmin" 2>/dev/null || true
+    # pkill only sends the signal and returns immediately — it doesn't wait
+    # for the process to actually exit and release its listening socket.
+    # Under network_mode: host there's no Docker-managed port mapping to
+    # tear down, so the next container's bind attempt races however long
+    # this process actually takes to die. Wait for it (briefly) instead of
+    # racing the next container's startup — it retries too now, but a
+    # clean handoff here means it usually shouldn't need to.
+    if pkill -f "easy-asterisk-webadmin" 2>/dev/null; then
+        for i in $(seq 1 20); do
+            pgrep -f "easy-asterisk-webadmin" >/dev/null 2>&1 || break
+            sleep 0.1
+        done
+        pkill -9 -f "easy-asterisk-webadmin" 2>/dev/null || true
+    fi
     asterisk -rx "core stop now" 2>/dev/null || true
     exit 0
 }