claude: Add attention-bell hook so tmux flags Claude sessions needing input

Wire Stop and Notification hooks in ~/.claude/settings.json to a new
~/.claude/hooks/attention-bell.sh, which rings the terminal bell in the
session pane so tmux monitor-bell flags the background window.

The hook runs detached (no controlling tty), so it walks its process
ancestry to the claude process and writes the BEL to that pane tty.

Also replaces the dead settings.json symlink (pointed at a now-missing
~/wrk/claude path) with a real tracked file.

.claude/hooks/attention-bell.sh

@@ -0,0 +1,21 @@
+#!/bin/sh
+# attention-bell.sh — ring the terminal bell in this Claude session's tmux pane
+# so tmux's monitor-bell flags the (background) window red in the status bar.
+#
+# Claude Code runs hooks as detached subprocesses: they have no controlling
+# terminal, so /dev/tty is unavailable here. But the parent-process chain up to
+# the `claude` process stays intact, and `claude` itself holds the pane's pty.
+# So we walk ancestry to find it and write the bell straight to that tty.
+# (Writing a bare BEL to an explicit /dev/pts/N works even from a detached
+# process — verified against tmux's window_bell_flag.)
+
+pid=$PPID
+while [ "$pid" -gt 1 ] 2>/dev/null; do
+	if [ "$(ps -o comm= -p "$pid" 2>/dev/null)" = claude ]; then
+		tty=$(ps -o tty= -p "$pid" 2>/dev/null | tr -d ' ')
+		[ -n "$tty" ] && [ "$tty" != '?' ] && printf '\a' > "/dev/$tty"
+		exit 0
+	fi
+	pid=$(ps -o ppid= -p "$pid" 2>/dev/null | tr -d ' ')
+	[ -z "$pid" ] && break
+done

.claude/settings.json

@@ -1 +0,0 @@
-/home/alexion/wrk/claude/settings.json

.claude/settings.json

@@ -0,0 +1,18 @@
+{
+  "hooks": {
+    "Stop": [
+      {
+        "hooks": [
+          { "type": "command", "command": "~/.claude/hooks/attention-bell.sh" }
+        ]
+      }
+    ],
+    "Notification": [
+      {
+        "hooks": [
+          { "type": "command", "command": "~/.claude/hooks/attention-bell.sh" }
+        ]
+      }
+    ]
+  }
+}