The mesh's own files for a module are placed by the mesh, not the definition (issue 174)

48 definitions stop naming /var/lib/mesh/<module>: the directory says `place: "mesh"`, the two
subdirectories beneath it (gitea's runtime state, anthropic-manager's output) state their path
beneath it, and every credential, binding, merged file and mount names it as ${dir:mesh-state}.
Resolved on the default root, every definition names exactly the paths it named before —
TestPlacedDirectoriesKeepTheirPaths in mesh-controller, run over both checkouts. Needs the
controller that knows the word (mesh-controller, same branch) one release ahead.

modules/model-usage/module.json

@@ -23,14 +23,14 @@
     "*.usage.*"
   ],
   "own-secrets": {
-    "broker": "/var/lib/mesh/model-usage/broker"
+    "broker": "${dir:mesh-state}/broker"
   },
   "resources": [
     {
       "id": "mesh-state",
       "type": "directory",
-      "path": "/var/lib/mesh/model-usage",
-      "mode": "0700"
+      "mode": "0700",
+      "place": "mesh"
     },
     {
       "id": "state",
@@ -52,7 +52,7 @@
       "image": "mesh-runtime-model-usage@sha256:0000000000000000000000000000000000000000000000000000000000000000",
       "network": "host",
       "volumes": [
-        "/var/lib/mesh/model-usage/broker:/run/secrets/broker:ro",
+        "${dir:mesh-state}/broker:/run/secrets/broker:ro",
         "${dir:state}:/run/state",
         "${dir:state}/database.url:/run/secrets/database-url:ro"
       ],