build: escalate - a case left too long goes up to another desk with the same buttons

escalate: { <stage>: { days, to: <group> } } on a need adds a stage
<stage>_escalated the clock enters, with the same moves out of it; the
group's desk lists exactly those cases with those buttons, and the
desk that had it keeps it and may send it up itself. Not a mail: a
desk job. The vel's help requests go up to styret after a week.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GT37Z1Xtfd9pUuQtMTg6Yt

src/plan.rs

@@ -153,6 +153,11 @@ rest. Each is one line in the plan, and the builder does the wiring:
   moment the case gets there; `deadlines` lets a stage end on its own
   (a notice that expires, a request nobody took up); `invites_by` lets
   a desk bring a person in without anyone touching an admin tool.
+- **Let nothing wait unseen.** `escalate: { open: { days: 7, to: styret } }`
+  sends a case nobody has moved in a week up to another group's desk,
+  where it sits with the same buttons until someone finishes it; the
+  desk that had it keeps it too, and may send it up itself. A desk job,
+  not a mail: the group sees it when they sit down.
 - **Let one record answer another.** A need `about` another need is
   one answer per record of it, from that record's own row on the
   public list: a neighbour saying "I can lend you that" to a notice, a