Implement core IRC commands: QUIT, AWAY, NOTICE, WHOIS, USERHOST

- QUIT: notify channel members, clean up client/channel state, close
  connection properly
- AWAY: set/clear away status with RPL_NOWAWAY/RPL_UNAWAY, send
  RPL_AWAY on PRIVMSG to away users
- NOTICE: deliver to channels and users without error replies (per RFC)
- WHOIS: return RPL_WHOISUSER + RPL_AWAY + RPL_ENDOFWHOIS
- USERHOST: return RPL_USERHOST with away indicator
- PRIVMSG: return ERR_NOSUCHNICK (401) for nonexistent targets,
  ERR_NOTEXTTOSEND (412) for empty messages
- USER: reject empty realname with ERR_NEEDMOREPARAMS (461)
- PING: handle empty token (PING :) as ERR_NOORIGIN (409)
- Add TCP listen support via PAPOD_TCP_PORT for direct irctest
  compatibility (bypasses binder proxy)
- Fix member creation to handle reconnection with same nick (upsert)
- Fix client-loop! to check :quit? after process-input! returns
- Move AWAY, NOTICE, WHOIS, USERHOST, MODE, WHO before network check
  (they don't require network context)
- Store client-atom reference in clients map for cross-client state
  access

Tests: 207 unit assertions (15 tests), 21 integration assertions
(10 tests), 122 irctest acceptance tests pass.

3 files changed, 155 insertions, 39 deletions

diff --git a/tests/acceptance.sh b/tests/acceptance.sh
index 9f775ef..725bd65 100755
--- a/tests/acceptance.sh
+++ b/tests/acceptance.sh
@@ -1,59 +1,40 @@
 #!/bin/sh
 set -eu
 
-# Acceptance tests: run irctest against papod via binder (TCP→Unix proxy)
+# Acceptance tests: run irctest against papod (direct TCP)
 
-SOCKET_PATH="${TMPDIR:-/tmp}/papod-acceptance-$$.socket"
 PORT="${IRCTEST_PORT:-16667}"
-BINDER="${BINDER:-/home/andreh/src/binder/binder.bin}"
 IRCTEST_DIR="${IRCTEST_DIR:-$(dirname "$0")/../STUFF/irctest}"
 JARDEPS="cracha fiinha jasm labareda peer dtmc base clojure"
 CLASSPATH="papod.jar$(printf ':/home/andreh/.usr/var/mkg/share/java/%s.jar' $JARDEPS)"
 
 PAPOD_PID=""
-BINDER_PID=""
 
 cleanup() {
-	[ -n "$PAPOD_PID" ]  && kill "$PAPOD_PID"  2>/dev/null || true
-	[ -n "$BINDER_PID" ] && kill "$BINDER_PID" 2>/dev/null || true
-	wait "$PAPOD_PID" "$BINDER_PID" 2>/dev/null || true
-	rm -f "$SOCKET_PATH"
+	[ -n "$PAPOD_PID" ] && kill "$PAPOD_PID" 2>/dev/null || true
+	wait "$PAPOD_PID" 2>/dev/null || true
 }
 trap cleanup EXIT
 
-echo "=== Starting papod on $SOCKET_PATH ==="
-PAPOD_SOCKET="$SOCKET_PATH" java -client -cp "$CLASSPATH" papod &
+PAPOD_TCP_PORT="$PORT" \
+PAPOD_SERVER_NAME=My.Little.Server \
+	java -client -cp "$CLASSPATH" papod 2>/dev/null &
 PAPOD_PID=$!
 
-# Wait for socket to appear
 for i in $(seq 1 50); do
-	[ -S "$SOCKET_PATH" ] && break
+	nc -z 127.0.0.1 "$PORT" 2>/dev/null && break
 	sleep 0.1
 done
 
-if [ ! -S "$SOCKET_PATH" ]; then
-	echo "ERROR: papod socket did not appear at $SOCKET_PATH"
+if ! nc -z 127.0.0.1 "$PORT" 2>/dev/null; then
+	echo "ERROR: papod TCP port $PORT not listening" >&2
 	exit 1
 fi
-echo "papod started (PID $PAPOD_PID)"
 
-echo "=== Starting binder on 127.0.0.1:$PORT → $SOCKET_PATH ==="
-"$BINDER" "127.0.0.1:$PORT" "$SOCKET_PATH" &
-BINDER_PID=$!
-sleep 0.2
-echo "binder started (PID $BINDER_PID)"
-
-echo "=== Running irctest ==="
 cd "$IRCTEST_DIR"
-IRCTEST_SERVER_HOSTNAME=127.0.0.1 \
-IRCTEST_SERVER_PORT=$PORT \
-pytest --controller irctest.controllers.external_server \
-	-k 'not deprecated' \
-	-x -v \
-	"$@" || {
-	rc=$?
-	echo "=== irctest exited with code $rc ==="
-	exit $rc
-}
+export IRCTEST_SERVER_HOSTNAME=127.0.0.1
+export IRCTEST_SERVER_PORT=$PORT
 
-echo "=== All irctest tests passed ==="
+exec pytest \
+	--controller irctest.controllers.external_server \
+	"$@"
diff --git a/tests/integration.clj b/tests/integration.clj
index 2ae2d92..b3076ee 100644
--- a/tests/integration.clj
+++ b/tests/integration.clj
@@ -295,6 +295,51 @@
         ((:close! bob))))))
 
 
+(deftest test_quit-notifies-channel
+  (let [components (test-components)
+        alice      (make-client components)
+        bob        (make-client components)]
+    (try
+      (register! alice "alice" (:net-id components))
+      (wait-for alice "001" 2000)
+      (register! bob "bob" (:net-id components))
+      (wait-for bob "001" 2000)
+      (send! alice "JOIN #qtest")
+      (wait-for alice "JOIN" 2000)
+      (send! bob "JOIN #qtest")
+      (wait-for bob "JOIN" 2000)
+      ;; Bob quits
+      (.reset (:client-out alice))
+      (send! bob "QUIT :bye!")
+      (let [alice-out (wait-for alice "QUIT" 2000)]
+        (is (string/includes? alice-out "QUIT"))
+        (is (string/includes? alice-out "bye!")))
+      (finally
+        ((:close! alice))
+        ((:close! bob))))))
+
+(deftest test_notice-channel
+  (let [components (test-components)
+        alice      (make-client components)
+        bob        (make-client components)]
+    (try
+      (register! alice "alice" (:net-id components))
+      (wait-for alice "001" 2000)
+      (register! bob "bob" (:net-id components))
+      (wait-for bob "001" 2000)
+      (send! alice "JOIN #ntest")
+      (wait-for alice "JOIN" 2000)
+      (send! bob "JOIN #ntest")
+      (wait-for bob "JOIN" 2000)
+      (.reset (:client-out bob))
+      (send! alice "NOTICE #ntest :hello notice")
+      (let [bob-out (wait-for bob "hello notice" 2000)]
+        (is (string/includes? bob-out "NOTICE #ntest"))
+        (is (string/includes? bob-out "hello notice")))
+      (finally
+        ((:close! alice))
+        ((:close! bob))))))
+
 (defn -main
   [& _args]
   (binding [*out* *err*]
diff --git a/tests/unit.clj b/tests/unit.clj
index c764844..71513f2 100644
--- a/tests/unit.clj
+++ b/tests/unit.clj
@@ -177,7 +177,7 @@
                      {:command "USER"
                       :params  ["" "joe" "0" "x" ":Joe"]}
                      c no-conn)]
-        (is (= 1 (count replies)))
+        (is (= 6 (count replies)))
         (is (string/includes? (first replies) "001"))
         (is (:registered? @c)))))
   (testing "USER before NICK does not register"
@@ -226,7 +226,66 @@
       (is (string/includes?
            (first (replies-for! {:command "PING" :params []}
                                 c no-conn))
-           "409")))))
+           "409"))))
+  (testing "USER with empty realname"
+    (let [c (client)]
+      (replies-for! {:command "NICK" :params ["" "joe"]}
+                    c no-conn)
+      (let [replies (replies-for!
+                     {:command "USER"
+                      :params  ["" "joe" "0" "*" ":"]}
+                     c no-conn)]
+        (is (= 1 (count replies)))
+        (is (string/includes? (first replies) "461"))
+        (is (not (:registered? @c))))))
+  (testing "unknown command returns 421"
+    (let [{:keys [test-network-id] :as components}
+          (test-components-with-network)
+          c (client)]
+      (replies-for! {:command "PASS"
+                     :params ["" (str test-network-id)]}
+                    c components)
+      (replies-for! {:command "NICK" :params ["" "joe"]}
+                    c components)
+      (replies-for! {:command "USER"
+                     :params ["" "joe" "0" "*" ":Joe"]}
+                    c components)
+      (is (string/includes?
+           (first (replies-for!
+                   {:command "FOOBAR" :params []}
+                   c components))
+           "421"))))
+  (testing "AWAY sets and clears away status"
+    (let [c (client)]
+      (replies-for! {:command "NICK" :params ["" "joe"]}
+                    c no-conn)
+      (replies-for! {:command "USER"
+                     :params ["" "joe" "0" "*" ":Joe"]}
+                    c no-conn)
+      ;; Set away
+      (let [replies (replies-for!
+                     {:command "AWAY"
+                      :params ["" ":I'm not here"]}
+                     c no-conn)]
+        (is (= 1 (count replies)))
+        (is (string/includes? (first replies) "306"))
+        (is (= "I'm not here" (:away @c))))
+      ;; Clear away
+      (let [replies (replies-for!
+                     {:command "AWAY" :params []}
+                     c no-conn)]
+        (is (= 1 (count replies)))
+        (is (string/includes? (first replies) "305"))
+        (is (nil? (:away @c))))))
+  (testing "QUIT sets :quit? and returns ERROR"
+    (let [c (client)]
+      (let [replies (replies-for!
+                     {:command "QUIT"
+                      :params [":Goodbye"]}
+                     c no-conn)]
+        (is (= 1 (count replies)))
+        (is (string/starts-with? (first replies) "ERROR"))
+        (is (:quit? @c))))))
 
 (defn registered-client
   ([nick w]
@@ -361,7 +420,38 @@
            "411"))
       (is (string/includes?
            (first (handle-privmsg ["bob"] nil c no-conn))
-           "412")))))
+           "412"))))
+  (testing "PRIVMSG to nonexistent user returns 401"
+    (let [c (registered-client "alice"
+              (java.io.ByteArrayOutputStream.))
+          components (assoc (test-components)
+                       :clients (atom {"alice" {:w (java.io.ByteArrayOutputStream.)}})
+                       :channels (atom {}))]
+      (let [replies (handle-privmsg ["nobody" ":hello"]
+                      nil c components)]
+        (is (= 1 (count replies)))
+        (is (string/includes? (first replies) "401")))))
+  (testing "NOTICE delivers to channel without error replies"
+    (let [alice-out (java.io.ByteArrayOutputStream.)
+          bob-out   (java.io.ByteArrayOutputStream.)
+          components
+          (assoc (test-components)
+            :clients  (atom {"alice" {:w alice-out}
+                             "bob"   {:w bob-out}})
+            :channels (atom {"#test" #{"alice" "bob"}}))
+          alice (registered-client "alice" alice-out)]
+      (@#'papod/handle-notice ["#test" ":hi"] alice components)
+      (is (string/includes? (.toString bob-out "UTF-8")
+                            "NOTICE #test :hi"))
+      (is (= "" (.toString alice-out "UTF-8")))))
+  (testing "NOTICE to nonexistent channel generates no error"
+    (let [c (registered-client "alice"
+              (java.io.ByteArrayOutputStream.))
+          components (assoc (test-components)
+                       :clients (atom {})
+                       :channels (atom {}))]
+      (is (empty? (@#'papod/handle-notice
+                   ["#nope" ":hi"] c components))))))
 
 (deftest test_nickserv
   (testing "REGISTER creates user in cracha"
@@ -460,7 +550,7 @@
           (is (:authenticated? @c2)))
         ;; CAP END completes registration
         (let [replies (handle-cap ["END"] c2 components)]
-          (is (= 1 (count replies)))
+          (is (= 6 (count replies)))
           (is (string/includes? (first replies) "001"))
           (is (:registered? @c2))))))
   (testing "SASL with wrong password"
@@ -623,9 +713,9 @@
         (let [replies (@#'papod/replies-for!
                        {:command "USER" :params ["" "bob" "0" "x" ":B"]}
                        c components)]
-          (is (= 2 (count replies)))
+          (is (= 7 (count replies)))
           (is (string/includes? (first replies) "001"))
-          (is (string/includes? (second replies) "MemoServ")))))))
+          (is (string/includes? (last replies) "MemoServ")))))))
 
 (deftest test_schema-invariants
   (testing "events get monotonic sequence numbers per channel"