A definition names no host path for its own data

Twenty-eight modules' data directories are placed: the root as place ".", a sub-directory named by
its id, and every host-side reference — binds, secrets, own secrets, grants, receives, file paths,
mounts, env-files — as ${dir:<id>}. Resolved on the default root every path is the one the manifest
named before, which the controller's TestPlacedDirectoriesKeepTheirPaths proves over both checkouts;
so no data moves and no machine sees a change. Five directories whose id is not their last segment
keep their path as a placement (novox/hq issue 119, ADR 0112, design 27).

modules/route-proxy/module.json

@@ -15,15 +15,15 @@
     "route": {}
   },
   "receives": {
-    "route": "/var/lib/route-proxy/routes/mesh.json"
+    "route": "${dir:routes-dir}/mesh.json"
   },
   "requires": [
     "acme-ca",
     "internal-acme-ca"
   ],
   "binds": {
-    "acme-ca": "/var/lib/route-proxy/acme-ca.json",
-    "internal-acme-ca": "/var/lib/route-proxy/internal-acme-ca.json"
+    "acme-ca": "${dir:state}/acme-ca.json",
+    "internal-acme-ca": "${dir:state}/internal-acme-ca.json"
   },
   "listens": [
     {
@@ -45,8 +45,8 @@
     {
       "id": "state",
       "type": "directory",
-      "path": "/var/lib/route-proxy",
-      "mode": "0700"
+      "mode": "0700",
+      "place": "."
     },
     {
       "id": "routes-dir",
@@ -69,14 +69,14 @@
     {
       "id": "acme-env",
       "type": "file",
-      "path": "/var/lib/route-proxy/acme.env",
+      "path": "${dir:state}/acme.env",
       "mode": "0600",
       "content": "ACME_DIRECTORY=https://${bound:acme-ca:at}:${bound:acme-ca:port}${bound:acme-ca:path}\nACME_ROOTS=https://${bound:acme-ca:at}:${bound:acme-ca:port}${bound:acme-ca:roots}\nACME_ROOTS_PATH=${bound:acme-ca:roots}\n"
     },
     {
       "id": "internal-acme-env",
       "type": "file",
-      "path": "/var/lib/route-proxy/internal-acme.env",
+      "path": "${dir:state}/internal-acme.env",
       "mode": "0600",
       "content": "INTERNAL_ACME_DIRECTORY=https://${bound:internal-acme-ca:at}:${bound:internal-acme-ca:port}${bound:internal-acme-ca:path}\nINTERNAL_ACME_ROOTS=https://${bound:internal-acme-ca:at}:${bound:internal-acme-ca:port}${bound:internal-acme-ca:roots}\nINTERNAL_ACME_ROOTS_PATH=${bound:internal-acme-ca:roots}\n"
     },
@@ -88,10 +88,10 @@
       "run-once": true,
       "network": "host",
       "env-file": [
-        "/var/lib/route-proxy/acme.env"
+        "${dir:state}/acme.env"
       ],
       "volumes": [
-        "/var/lib/route-proxy/ca:/ca"
+        "${dir:ca-dir}:/ca"
       ],
       "args": [
         "sh",
@@ -110,10 +110,10 @@
       "run-once": true,
       "network": "host",
       "env-file": [
-        "/var/lib/route-proxy/internal-acme.env"
+        "${dir:state}/internal-acme.env"
       ],
       "volumes": [
-        "/var/lib/route-proxy/ca:/ca"
+        "${dir:ca-dir}:/ca"
       ],
       "args": [
         "sh",
@@ -131,13 +131,13 @@
       "artifact": "server",
       "network": "host",
       "env-file": [
-        "/var/lib/route-proxy/acme.env",
-        "/var/lib/route-proxy/internal-acme.env"
+        "${dir:state}/acme.env",
+        "${dir:state}/internal-acme.env"
       ],
       "volumes": [
-        "/var/lib/route-proxy/routes:/routes:ro",
-        "/var/lib/route-proxy/acme:/acme",
-        "/var/lib/route-proxy/ca:/ca:ro"
+        "${dir:routes-dir}:/routes:ro",
+        "${dir:acme-cache}:/acme",
+        "${dir:ca-dir}:/ca:ro"
       ],
       "env": {
         "ROUTES": "/routes/mesh.json",