fix: unify exec approval ids

docs/tools/exec.md

@@ -38,6 +38,7 @@ Notes:
 ## Config
 
 - `tools.exec.notifyOnExit` (default: true): when true, backgrounded exec sessions enqueue a system event and request a heartbeat on exit.
+- `tools.exec.approvalRunningNoticeMs` (default: 10000): emit a single “running” notice when an approval-gated exec runs longer than this (0 disables).
 - `tools.exec.host` (default: `sandbox`)
 - `tools.exec.security` (default: `deny` for sandbox, `allowlist` for gateway + node when unset)
 - `tools.exec.ask` (default: `on-miss`)
@@ -92,6 +93,11 @@ Example:
 Sandboxed agents can require per-request approval before `exec` runs on the gateway or node host.
 See [Exec approvals](/tools/exec-approvals) for the policy, allowlist, and UI flow.
 
+When approvals are required, the exec tool returns immediately with
+`status: "approval-pending"` and an approval id. Once approved (or denied / timed out),
+the Gateway emits system events (`Exec finished` / `Exec denied`). If the command is still
+running after `tools.exec.approvalRunningNoticeMs`, a single `Exec running` notice is emitted.
+
 ## Allowlist + safe bins
 
 Allowlist enforcement matches **resolved binary paths only** (no basename matches). When