fix: honor heartbeat timeoutSeconds (#64491)

docs/.generated/config-baseline.sha256

@@ -1,4 +1,4 @@
-1977d4698bb80b9aa99315f1114a61b5692bd5630f2ac4a225d81ddc5459d588  config-baseline.json
-d1ee5c4d01deac5cf8ea284cafcd8b6c952b2554d40947d2463d08e314acfcda  config-baseline.core.json
+995d3ffac3a4a982f9a97d7583c081eb8b48e2d1ed80fa4db5633f2b5c0f543a  config-baseline.json
+44b2f2fc7fe0092346d33a16936c576e8767b83d13808491e0cb418cd69ecf1b  config-baseline.core.json
 e1f94346a8507ce3dec763b598e79f3bb89ff2e33189ce977cc87d3b05e71c1d  config-baseline.channel.json
-0fb10e5cb00e7da2cd07c959e0e3397ecb2fdcf15e13a7eae06a2c5b2346bb10  config-baseline.plugin.json
+6c19997f1fb2aff4315f2cb9c7d9e299b403fbc0f9e78e3412cc7fe1c655f222  config-baseline.plugin.json

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.",
         },
       },