fix: honor heartbeat timeoutSeconds (#64491)

docs/gateway/configuration-reference.md

@@ -1224,6 +1224,7 @@ Periodic heartbeat runs.
         prompt: "Read HEARTBEAT.md if it exists...",
         ackMaxChars: 300,
         suppressToolErrorWarnings: false,
+        timeoutSeconds: 45,
       },
     },
   },
@@ -1233,6 +1234,7 @@ Periodic heartbeat runs.
 - `every`: duration string (ms/s/m/h). Default: `30m` (API-key auth) or `1h` (OAuth auth). Set to `0m` to disable.
 - `includeSystemPromptSection`: when false, omits the Heartbeat section from the system prompt and skips `HEARTBEAT.md` injection into bootstrap context. Default: `true`.
 - `suppressToolErrorWarnings`: when true, suppresses tool error warning payloads during heartbeat runs.
+- `timeoutSeconds`: maximum time in seconds allowed for a heartbeat agent turn before it is aborted. Leave unset to use `agents.defaults.timeoutSeconds`.
 - `directPolicy`: direct/DM delivery policy. `allow` (default) permits direct-target delivery. `block` suppresses direct-target delivery and emits `reason=dm-blocked`.
 - `lightContext`: when true, heartbeat runs use lightweight bootstrap context and keep only `HEARTBEAT.md` from workspace bootstrap files.
 - `isolatedSession`: when true, each heartbeat runs in a fresh session with no prior conversation history. Same isolation pattern as cron `sessionTarget: "isolated"`. Reduces per-heartbeat token cost from ~100K to ~2-5K tokens.

docs/gateway/heartbeat.md

@@ -146,6 +146,7 @@ Example: two agents, only the second agent runs heartbeats.
           every: "1h",
           target: "whatsapp",
           to: "+15551234567",
+          timeoutSeconds: 45,
           prompt: "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.",
         },
       },