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/mongodb/module.json

@@ -40,15 +40,15 @@
   },
   "own-secrets": {
     "root": "${dir:state}/root.secret",
-    "broker": "/var/lib/mesh/mongodb/broker"
+    "broker": "${dir:mesh-state}/broker"
   },
   "secrets-owner": "999:999",
   "resources": [
     {
       "id": "mesh-state",
       "type": "directory",
-      "path": "/var/lib/mesh/mongodb",
-      "mode": "0700"
+      "mode": "0700",
+      "place": "mesh"
     },
     {
       "id": "state",
@@ -95,7 +95,7 @@
       "name": "mesh-mongodb",
       "network": "mongodb",
       "volumes": [
-        "/var/lib/mesh/mongodb/broker:/run/secrets/broker:ro",
+        "${dir:mesh-state}/broker:/run/secrets/broker:ro",
         "${dir:grants}:${dir:grants}:ro",
         "${dir:state}/root.secret:/run/secrets/root:ro"
       ],