Address PR review feedback (#1432)

- delimiter-safe foreach instance-id resolution via IR-validated candidates
- restart watcher handles binding removal/defer-flip and re-keys the reverse
  heartbeat guard on agent change/delete
- governing-node stamp owned by the pass-initiating foreach instance (race fix)
- editor: policy-escalation confirm/retry handshake on save; foreach children
  inherit the override note; project-scoped agent fetches; picker disabled on
  registry fetch error; column-agent strings in the canonical i18n catalog
- tests: update-tool escalation surface, PATCH escalation route, parity bound
  to run-derived stages, try/finally cleanup, deterministic event waits,
  symmetric defer surfaces, binding-release regression

docs/workflow-steps.md

@@ -65,7 +65,7 @@ The `workflowColumns` track introduces **IR v2** (`version: "v2"`), where a work
 
 A v2 column can optionally name a **permanent agent** from the agent registry, staffing every card that flows through it once instead of node-by-node or task-by-task. The binding is a first-class optional field on the column (not a trait — traits are board-transition policy; this is execution identity):
 
-```
+```ts
 { id: "review", name: "Review", traits: [],
   agent: { agentId: "agent-001", mode: "defer" | "override" } }
 ```