chore(hooks): notify-attention — bell + OSC 777 toast when Claude needs input

Notification hook (permission_prompt|idle_prompt|agent_needs_input|
elicitation_*) returns BEL x2 + OSC 777 via the terminalSequence JSON
field (hooks have no controlling TTY). Client side over Remote-SSH:
VS Code accessibility.signals.terminalBell sound:on for the beep,
wenbopan.vscode-terminal-osc-notifier extension for the Windows toast.

hooks/notify-attention.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+# Notification hook — signal the user through the terminal when Claude
+# needs input (permission prompt, question, idle wait).
+#
+# Runs on the remote (Linux); the only channel that crosses SSH into the
+# VS Code client is the terminal stream. Hooks have no controlling TTY,
+# so the sequence goes through the supported `terminalSequence` JSON
+# output field and Claude Code writes it to the terminal:
+#   - BEL x2 (double beep) -> sound, needs VS Code setting
+#     accessibility.signals.terminalBell { "sound": "on" }
+#   - OSC 777 notify -> Windows toast via the client-side extension
+#     "Terminal Notification" (wenbopan.vscode-terminal-osc-notifier)
+# Both are invisible no-ops in terminals that ignore them.
+set -u
+
+msg=$(jq -r '.message // .notification_type // empty' 2>/dev/null \
+  | tr -d '\000-\037' | cut -c1-200)
+[ -n "$msg" ] || msg="Claude Code needs your input"
+
+bell=$(printf '\a')
+esc=$(printf '\033')
+seq="${bell}${bell}${esc}]777;notify;Claude Code;${msg}${esc}\\"
+jq -cn --arg seq "$seq" '{suppressOutput: true, terminalSequence: $seq}'
+exit 0

settings.json

@@ -273,6 +273,19 @@
         ]
       }
     ],
+    "Notification": [
+      {
+        "matcher": "permission_prompt|idle_prompt|agent_needs_input|elicitation_dialog|elicitation_url_dialog",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "bash ~/.claude/hooks/notify-attention.sh",
+            "timeout": 5,
+            "statusMessage": "Ringing terminal bell..."
+          }
+        ]
+      }
+    ],
     "UserPromptSubmit": [
       {
         "hooks": [