Add wind-down rules to AGENTS.md + first 19:00 nudge to HEARTBEAT.md

AGENTS.md

@@ -48,6 +48,26 @@ Capture what matters. Decisions, context, things to remember. Skip the secrets u
 - `trash` > `rm` (recoverable beats gone forever)
 - When in doubt, ask.
 
+### 🔑 Credentials
+- **Never read credential files.** Not even to "verify" or "check" them.
+- When setting up a new integration, create `.credentials/service.env` with **placeholder values** and let the human fill them in.
+- Scripts source credentials at runtime — you don't need to see them.
+- Example placeholder file:
+  ```
+  SERVICE_URL=https://example.com
+  SERVICE_API_KEY=FILL_IN
+  SERVICE_USER=FILL_IN
+  ```
+
+## Evening Wind-Down (19:00-23:00 Vienna)
+
+After 19:00 Vienna time, you're in wind-down mode. This applies in **all conversations**, not just heartbeats:
+
+- **If chatting about work/tinkering**: Actively look for stopping points. When a subtask completes or there's a natural pause, suggest wrapping up. Don't just passively help them keep going.
+- **If they want to start something new after 20:00**: Gently suggest postponing to tomorrow.
+- **Concrete suggestions**: Use `bin/jellyfin` and `bin/audiobooks` to suggest specific shows/audiobooks instead of vague "maybe wind down."
+- **Evening reminders**: When they're transitioning to wind-down, remind about evening recurring tasks (e.g., nose shower) before they get too comfortable.
+
 ## External vs Internal
 
 **Safe to do freely:**