radarr: its config dir is placed, its image is the one ace runs

The manifest named /services/radarr/config and /var/lib/mesh/radarr/route.json, host
paths ADR 0112 takes out of definitions. The config dir is now a pathless ${dir:config}
(0700, 1000:1000) mounted into the server and, read-only, into the runtime that reads the
API key from config.xml; the route binding lives in a placed state dir, as jackett and
searxng do. /var/lib/mesh/radarr stays for the broker secret.

The image is pinned to 6.4.4.10685-ls317, the digest ace runs today. The old pin
(6.3.0.10514-ls314) was older than the running version, and Radarr migrates its database
forward on start, so pointing the older build at ace's data is not safe.

The container mount points stay /movies and /downloads: Radarr's database stores its root
folder and the download clients' reported paths under exactly those names, and there are
no remote path mappings to absorb a change. The generic access paths stay; ace's
(/storage/media/movies, /storage/downloads) and its media owner 1001:2000 wait on hq 153.

Based on feat/servarr-api-provision (#156), which makes radarr provide radarr-api.

Verified: catalogue key tests with MESH_CATALOGUE set (73 manifests parsed, not skipped);
a throwaway container of the pinned image on a fresh 0700 1000:1000 config dir answers
/ping, serves the v3 API with the key it generated and refuses a wrong one (401), accepts
/movies as a writable root folder; the runtime's client discovers the key from that
config.xml and reads the queue.

modules/radarr/module.json

@@ -31,7 +31,7 @@
       "port": 7878,
       "protocol": "tcp",
       "from": "mesh",
-      "why": "managing films"
+      "why": "managing films: its web UI, and the API other modules reach as radarr-api"
     }
   ],
   "accesses": [
@@ -51,10 +51,15 @@
       "path": "/var/lib/mesh/radarr",
       "mode": "0700"
     },
+    {
+      "id": "state",
+      "type": "directory",
+      "mode": "0700",
+      "place": "."
+    },
     {
       "id": "config",
       "type": "directory",
-      "path": "/services/radarr/config",
       "mode": "0700",
       "owner": "1000:1000"
     },
@@ -62,7 +67,7 @@
       "id": "server",
       "type": "container",
       "name": "radarr",
-      "image": "lscr.io/linuxserver/radarr@sha256:119aaa4a4f7349bcd2a136c5373a0d7925b5479915c7dfe0c0ad352db2a6d438",
+      "image": "lscr.io/linuxserver/radarr@sha256:c960f2b52ec6542dbe6707c5a21e696a7c74fd8b17997454f4d10a55dacee133",
       "env": {
         "PUID": "1000",
         "PGID": "1000",
@@ -72,7 +77,7 @@
         "7878"
       ],
       "volumes": [
-        "/services/radarr/config:/config",
+        "${dir:config}:/config",
         "/services/media/movies:/movies",
         "/services/media/downloads:/downloads"
       ]
@@ -84,7 +89,7 @@
       "network": "host",
       "volumes": [
         "/var/lib/mesh/radarr/broker:/run/secrets/broker:ro",
-        "/services/radarr/config:/var/lib/radarr/config:ro"
+        "${dir:config}:/var/lib/radarr/config:ro"
       ],
       "env": {
         "MESH_BROKER_FILE": "/run/secrets/broker",
@@ -104,7 +109,7 @@
     }
   },
   "binds": {
-    "route": "/var/lib/mesh/radarr/route.json"
+    "route": "${dir:state}/route.json"
   },
   "build": {
     "on": [