docs(skills): add crunch-jobs and update voice-notify

Adds crunch-jobs skill for scheduling voice reminders, AI crunch jobs,
and script-based pipelines via crunch/talk.

Updates voice-notify with stdin piping examples and cancel-button
implementation notes.

skills/voice-notify/SKILL.md

@@ -38,6 +38,19 @@ ElevenLabs TTS voice notifications with a dismissable desktop popup. Audio playb
 talk "Build abgeschlossen. Alle 247 Tests erfolgreich."
 ```
 
+### Stdin (Pipe)
+
+```bash
+echo "Deployment fertig" | talk
+nixos-rebuild build 2>&1 | tail -3 | talk
+
+# AI agent print mode → talk
+pi -p "Review diesen Code" | talk
+opencode run "Erkläre diese Funktion" -q | talk
+```
+
+Argument has priority; if no argument is given, `talk` reads from stdin. This enables piping from any command or AI agent.
+
 ### After Task Completion
 
 ```bash
@@ -103,5 +116,5 @@ Set per-shell, per-user, or system-wide via Home-Manager `home.sessionVariables`
 
 - **No audio?** Check `ELEVENLABS_API_KEY` is set and has credits (HTTP 402 = no credits)
 - **No popup?** Ensure a notification daemon is running (`notify-send` needs a daemon)
-- **Popup stays after audio?** The poll-loop should close it; if not, DMS may handle actions differently
+- **Cancel button doesn't stop audio?** Fixed: the poll loop now uses `[ -s ]` (non-empty check) instead of `[ -f ]` (exists). The action file is created as empty by the shell redirect; it's only filled when the user clicks Abbrechen.
 - **`pw-play` doesn't work** — it can't decode MP3; `talk` uses `mpv` which handles all formats