feat: add heartbeat active hours

docs/gateway/configuration.md

@@ -1737,6 +1737,10 @@ Z.AI models are available as `zai/<model>` (e.g. `zai/glm-4.7`) and require
   `30m`. Set `0m` to disable.
 - `model`: optional override model for heartbeat runs (`provider/model`).
 - `includeReasoning`: when `true`, heartbeats will also deliver the separate `Reasoning:` message when available (same shape as `/reasoning on`). Default: `false`.
+- `activeHours`: optional local-time window that controls when heartbeats run.
+  - `start`: start time (HH:MM, 24h). Inclusive.
+  - `end`: end time (HH:MM, 24h). Exclusive. Use `"24:00"` for end-of-day.
+  - `timezone`: `"user"` (default), `"local"`, or an IANA timezone id.
 - `target`: optional delivery channel (`last`, `whatsapp`, `telegram`, `discord`, `slack`, `signal`, `imessage`, `none`). Default: `last`.
 - `to`: optional recipient override (channel-specific id, e.g. E.164 for WhatsApp, chat id for Telegram).
 - `prompt`: optional override for the heartbeat body (default: `Read HEARTBEAT.md if it exists (workspace context). Follow it strictly. Do not infer or repeat old tasks from prior chats. If nothing needs attention, reply HEARTBEAT_OK.`). Overrides are sent verbatim; include a `Read HEARTBEAT.md` line if you still want the file read.

docs/gateway/heartbeat.md

@@ -14,6 +14,7 @@ surface anything that needs attention without spamming you.
 2. Create a tiny `HEARTBEAT.md` checklist in the agent workspace (optional but recommended).
 3. Decide where heartbeat messages should go (`target: "last"` is the default).
 4. Optional: enable heartbeat reasoning delivery for transparency.
+5. Optional: restrict heartbeats to active hours (local time).
 
 Example config:
 
@@ -24,6 +25,7 @@ Example config:
       heartbeat: {
         every: "30m",
         target: "last",
+        // activeHours: { start: "08:00", end: "24:00", timezone: "user" },
         // includeReasoning: true, // optional: send separate `Reasoning:` message too
       }
     }
@@ -38,6 +40,8 @@ Example config:
   `Read HEARTBEAT.md if it exists (workspace context). Follow it strictly. Do not infer or repeat old tasks from prior chats. If nothing needs attention, reply HEARTBEAT_OK.`
 - The heartbeat prompt is sent **verbatim** as the user message. The system
   prompt includes a “Heartbeat” section and the run is flagged internally.
+- Active hours (`heartbeat.activeHours`) are checked in the configured timezone.
+  Outside the window, heartbeats are skipped until the next tick inside the window.
 
 ## What the heartbeat prompt is for