ADR 0199: a module that answers names declares its zone, and a node's hosts file is one module's

The per-node resolvers 0194 retires held two kinds of names that are neither nodes nor routes: the
lab's scenario machines and an operator's own lines. A zone a module declares is forwarded by the
mesh's resolver to that module; /etc/hosts is held per node through node-hosts-file, the operator's
lines in its kept region. Research 023 parks seats that define what their holder owns.

01-RESEARCH/023-a-seat-protocol-that-defines-what-its-holder-owns/00-overview.md

@@ -0,0 +1,37 @@
+---
+status: active
+initiated: 2026-10-03
+touches: [the seats, the seat protocol, the controller's ownership check, 03-DESIGN/01-to-be/26-the-seats.md]
+---
+
+# 023 — A seat protocol that defines what its holder owns
+
+## What is investigated
+
+**A seat is a definition — a protocol — and a module occupies it by implementing that protocol.**
+Today the protocol is what the holder accepts, emits and serves (ADR 0118, 0129, 0132): its verbs, as MCP
+tool definitions. This asks whether the protocol should also name the **files and directories the
+holder owns**, so that occupying the seat means owning them: `node-resolver-config` owns
+`/etc/resolv.conf`, `node-hosts-file` owns `/etc/hosts`, the intrusion prevention owns its jail file.
+
+The direction is the protocol's, not the holder's: the seat states what any holder must own; a module
+that wants the seat must declare those paths among its resources, or the controller refuses the claim
+as not implementing the seat. Two seats may not name one path.
+
+## Why
+
+Who owns a singular file is today answered by reading every manifest, and enforced only after the fact,
+when two modules on one machine both declare the same path. The question *which module owns
+`/etc/resolv.conf`?* came up on 2026-10-03 with no place to look it up. A seat that names the path answers
+it from the seat table, before any module is written, and makes "implements the seat" checkable.
+
+## What it touches
+
+- The seat definition and its table (ADR 0122) — a new part of the protocol.
+- The controller's ownership check (`checkResources`), which already refuses two modules owning one path.
+- Every node seat that is really about a file: `node-resolver-config`, `node-hosts-file`
+  ([ADR 0199](../../02-DECISIONS/0199-a-module-that-answers-names-declares-its-zone-and-a-nodes-hosts-file-is-one-modules.md)),
+  `node-intrusion-prevention`, `node-packet-filter`.
+
+Raised by the operator during the resolver work of ADRs 0194–0199 and parked there so that work was not
+widened by it.