fix: consistent usage errors for list, leave, status, who, log

list ignored --help and listed parties; leave and status ignored stray
arguments; who silently kept the last of several positionals; log took
a positional name that neither its usage nor the man page documents.
All now follow the parser convention of the other subcommands: help on
-h, exit 2 on an unknown flag or unexpected argument.

party

@@ -1090,10 +1090,7 @@ Usage: party log [--stop] [--party <name>]
 EOF
                 exit 0 ;;
             -*) echo "party log: unknown flag '$1'" >&2; exit 2 ;;
-            *)
-                if [ -z "$partyname" ]; then partyname="$1"; shift
-                else echo "party log: unexpected arg '$1'" >&2; exit 2; fi
-                ;;
+            *)  echo "party log: unexpected arg '$1'" >&2; exit 2 ;;
         esac
     done
 
@@ -1277,10 +1274,22 @@ EOF
     # the socket path.
     exec "$PARTY_TMUX" -S "$RR_SOCKET" "$@"
 }
-cmd_leave() {
+
+# Argv check for the subcommands that take no arguments. $1 = label.
+# A stray word is more likely a typo'd subcommand line than something
+# to ignore, so it is a usage error like everywhere else.
+_parse_no_args() {
+    label="$1"; shift
     case "${1:-}" in
-        -h|--help) echo "Usage: party leave"; exit 0 ;;
+        '') ;;
+        -h|--help) echo "Usage: party $label"; exit 0 ;;
+        -*) echo "party $label: unknown flag '$1'" >&2; exit 2 ;;
+        *)  echo "party $label: unexpected arg '$1'" >&2; exit 2 ;;
     esac
+}
+
+cmd_leave() {
+    _parse_no_args leave "$@"
 
     # Walk every live party; for each one we have any presence on
     # (either via __party_guest_$USER or as a client of the host's
@@ -1520,6 +1529,7 @@ cmd_detach() {
 }
 
 cmd_list() {
+    _parse_no_args list "$@"
     found=0 lines='' first_group='' mixed=0
     for rec in $(roster_list); do
         roster_read "$rec" || continue
@@ -1583,7 +1593,10 @@ cmd_who() {
                 echo "Usage: party who [--short] [--party name|--socket path]"
                 exit 0 ;;
             -*) echo "party who: unknown flag '$1'" >&2; exit 2 ;;
-            *)  partyname="$1"; shift ;;
+            *)
+                if [ -z "$partyname" ]; then partyname="$1"; shift
+                else echo "party who: unexpected arg '$1'" >&2; exit 2; fi
+                ;;
         esac
     done
 
@@ -1636,9 +1649,7 @@ cmd_who() {
 }
 
 cmd_status() {
-    case "${1:-}" in
-        -h|--help) echo "Usage: party status"; exit 0 ;;
-    esac
+    _parse_no_args status "$@"
 
     hosting='' joined=''
     for rec in $(roster_list); do