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.

03-DESIGN/01-to-be/08-connectivity.md

@@ -10,6 +10,7 @@ code:
   - mesh-host internal/apply (the service that reflects a rule set)
 updated: 2026-10-03
 decisions:
+  - 02-DECISIONS/0199-a-module-that-answers-names-declares-its-zone-and-a-nodes-hosts-file-is-one-modules.md
   - 02-DECISIONS/0196-a-node-asks-the-meshs-resolver-first-and-a-public-one-only-when-it-is-silent.md
   - 02-DECISIONS/0194-the-mesh-has-one-resolver-and-every-node-asks-it-for-the-meshs-names.md
   - 02-DECISIONS/0191-the-meshs-resolver-holds-only-the-meshs-own-names.md
@@ -377,6 +378,16 @@ member's resolver answers a LAN; a router pointing at one is moved first. *Check
 `/etc/resolv.conf` naming `mesh-resolver` then a public resolver, by no node but the holder answering
 DNS on any address, and by the router's DHCP DNS option naming the router.*
 
+**Names that are neither a node nor a route.** A module that answers names declares a zone (a
+setting) and the listen that answers it; the controller hands the `mesh-dns-resolver` holder every
+zone with its module's node address and published port, and the holder forwards that zone there and
+answers nothing in it itself — the lab answers `<machine>.incus` for its running scenarios this way.
+An operator's own names, unrelated to the mesh, live in `/etc/hosts`'s kept region, held per node by
+the `node-hosts-file` seat's holder and changed through its tools; the controller holds none of them
+([ADR 0199](../../02-DECISIONS/0199-a-module-that-answers-names-declares-its-zone-and-a-nodes-hosts-file-is-one-modules.md)).
+*Checked by the holder's configuration carrying one forwarding rule per declared zone, and by a push
+leaving the hosts file's operator region byte for byte.*
+
 *What follows describes the per-node resolver this replaces — how it was built and why the roles were
 split. The split stands; the serving role's scope is what moved.*
 
@@ -1021,6 +1032,8 @@ The list is worth having in one place, because it is most of the argument:
 
 - **One resolver ([ADR 0194](../../02-DECISIONS/0194-the-mesh-has-one-resolver-and-every-node-asks-it-for-the-meshs-names.md)).** Not built: every node still runs
   `node-dns-resolver`. The migration's four steps are in the record, in order.
+  Nor are zones or the hosts file's holder ([ADR 0199](../../02-DECISIONS/0199-a-module-that-answers-names-declares-its-zone-and-a-nodes-hosts-file-is-one-modules.md)): the
+  workstation moves to the one resolver only once both exist, its lab and operator names depending on them.
 
 - ~~**What happens when the hub is down.**~~ **Resolved** by
   [ADR 0006](../../02-DECISIONS/0006-the-substrate-and-the-control-plane.md), together with `06`'s

03-DESIGN/01-to-be/26-the-seats.md

@@ -12,6 +12,7 @@ code:
   - mesh-catalog modules/gitea/module.json
 updated: 2026-10-03
 decisions:
+  - 02-DECISIONS/0199-a-module-that-answers-names-declares-its-zone-and-a-nodes-hosts-file-is-one-modules.md
   - 02-DECISIONS/0194-the-mesh-has-one-resolver-and-every-node-asks-it-for-the-meshs-names.md
   - 02-DECISIONS/0161-what-deserves-a-seat.md
   - 02-DECISIONS/0131-everything-on-the-mesh-speaks-to-the-broker-seat.md
@@ -129,6 +130,7 @@ convention, which later seats departed from.
 | `mesh-build-machine` | `the-build-machine` | node | — | a builder |
 | `mesh-resolver` | — | mesh | — | the mesh's one resolver, holding every node's internal domain ([ADR 0194](../../02-DECISIONS/0194-the-mesh-has-one-resolver-and-every-node-asks-it-for-the-meshs-names.md)) |
 | ~~`mesh-dns-port`~~ | `the-dns-port` | node | — | retired by [ADR 0194](../../02-DECISIONS/0194-the-mesh-has-one-resolver-and-every-node-asks-it-for-the-meshs-names.md): the local resolver became the mesh's one |
+| `node-hosts-file` | — | node | — | owns `/etc/hosts`: the machine's own lines and the operator's kept region, changed through its verbs `entries`, `add`, `remove` ([ADR 0199](../../02-DECISIONS/0199-a-module-that-answers-names-declares-its-zone-and-a-nodes-hosts-file-is-one-modules.md)) |
 | `mesh-intrusion-prevention` | `the-intrusion-prevention` | node | — | an intrusion-prevention service |
 | `mesh-packet-filter` | `the-packet-filter` | node | — | the packet filter |
 | `mesh-private-network` | `the-private-network` | node | — | the private network the mesh runs over |