Issues 173 and 174 resolved; the installation check refuses at registration (ADR 0155)

A setting overrides a key a contribution or served fact declares and adds none; a provider that must
tell its consumers an operator's value declares it as ${setting:…} (173). The mesh's own files for a
module are a placed directory, `place: "mesh"`, and forty-eight definitions name no host path for
them (174). Registration refuses a definition naming an installation, the day the list emptied
rather than a release later (0155, progressive insight; 134). Designs 27 and 18 carry the rules.

03-DESIGN/01-to-be/18-building-a-module.md

@@ -234,7 +234,7 @@ counts as a copy and what as a base.
 
 | resource | is | a module may |
 |---|---|---|
-| `directory` | a directory with a mode and an owner | ✅ |
+| `directory` | a directory with a mode and an owner, **placed by the mesh** under the node's root: `place: "."` is the assignment's own root, `place: "mesh"` the mesh's directory for the module, a pathless one sits beneath the root by its id; a stated path is the placement for data that must stay where it is, and may itself sit beneath a placed one (`${dir:<id>}/…`). Everything else names it as `${dir:<id>}` ([issue 119](../../04-ISSUES/119-a-module-definition-decides-where-its-files-live/00-report.md), [174](../../04-ISSUES/174-the-meshs-own-files-for-a-module-are-placed-by-the-definition/00-report.md)) | ✅ |
 | `file` | literal content, with `${bound:…}`, `${secret:…}`, `${dir:…}`, `${port:…}`, `${machine:…}` and `${setting:…}` filled in — the last an operator's value from the assignment's settings, refused by name when unset ([ADR 0155](../../02-DECISIONS/0155-a-definition-names-no-installation-and-how-that-is-checked.md)) | ✅ |
 | `user` | a login | ✅ |
 | `access` | a pre-existing path it may use and must not own | ✅ |

03-DESIGN/01-to-be/27-a-module-requires-the-mesh-resolves.md

@@ -184,9 +184,21 @@ placeholders have, not yet the one requirement form below; they are phase 1's fi
 *Phase 3, in part (2026-09-30):* every definition's **own** data directory is placed; the conversion
 moved no data, proven by resolving both catalogues with the controller's rule and comparing
 ([issue 119](../../04-ISSUES/119-a-module-definition-decides-where-its-files-live/00-report.md)).
-What the mesh writes *for* a module is still placed by the definition
+What the mesh writes *for* a module was still placed by the definition
 ([issue 174](../../04-ISSUES/174-the-meshs-own-files-for-a-module-are-placed-by-the-definition/00-report.md)),
-which is the gap this design answered on 2026-09-26 and has not built.
+the gap this design answered on 2026-09-26; built later the same day: a directory saying
+`place: "mesh"` is `<root>/mesh/<module>`, a directory beneath a placed one states its path as
+`${dir:<id>}/<rest>` and moves with it, and the same proof — both catalogues resolved and compared —
+shows forty-eight definitions naming the paths they named before.
+
+*The operator's value travels only where it is asked for (2026-09-30,
+[issue 173](../../04-ISSUES/173-a-modules-settings-reach-every-fact-it-contributes/00-report.md)):*
+a setting overrides a key a contribution or a served fact declares and adds none; a file keeps taking
+any key. A provider that must tell its consumers an operator's value — a mail server's domain, an
+identity provider's issuer — declares it in what it serves as `${setting:<key>}`, and it is refused by
+name when nothing sets it. That is the contract half of this design's operator provider in the shape
+the placeholder allows: the definition says which values reach which requirement, and nothing else
+does. *How it is checked:* the unit tests named in issue 173, and the plan comparison that closed it.
 
 ## How a definition reads what was resolved
 
@@ -396,7 +408,9 @@ writes (`/var/lib/mesh/<module>`: sealed credentials, composed bindings) need a
 module-visible reservation. They do not: a module *requires* a `host-path` and receives a
 location; what the mesh writes for the module is the mesh's plumbing, placed where the mesh
 chooses and mounted in — never part of the module's contract. One reservation per
-requirement, `<root>/<module>/<name>`.
+requirement, `<root>/<module>/<name>`. *(Built 2026-09-30: the mesh's directory for a module is
+`<root>/mesh/<module>`, named in the definition as a placed directory and nowhere as a path —
+issue 174.)*
 
 **Resolution happens in the controller, at declaration composition.** The node receives
 concrete paths exactly as today — the wire format and the host's apply do not change for