nzbget: placed config, the build ace runs, its password a file, its API provided

The manifest named /services/nzbget/config and /var/lib/mesh/nzbget/config.json,
host paths ADR 0112 takes out of definitions. The config dir is now pathless
(${dir:config}); the runtime's config and route binding live in a placed state dir.

The image is pinned to v26.0-ls233, the digest ace runs. The old pin (v26.3-ls261)
is newer but unproven against ace's queue; moving up is a later, separate step.

The password own-secret reached the tools and nothing else, so a fresh machine ran
nzbget's well-known default while the tools held a minted value that matched
nothing. The server now reads it too, through the image's FILE__NZBGET_PASS (a
path in the environment, the value from a 0600 root file - ADR 0086), and both
restart on it. An adopted machine accepts its existing ControlPassword.

The tools assumed the control user is "nzbget"; they now read ControlUsername
from nzbget.conf on the read-only config mount (ace's is not "nzbget").

sonarr, radarr, lidarr and bookshelf reached nzbget by container name on HAL's
shared network. nzbget now provides nzbget-api (node scope: a download client
must share the consumer's download spool) and serves scheme, port, url-base and
username; the password is the operator-accepted pair credential, as for #156.
The web endpoint is routed (label nzbget). The runtime dials ${port:6789}, the
same line as #154.

Verified: catalogue tests with MESH_CATALOGUE set (not skipped); rendered for ace
with a pinned port and username setting; a throwaway of the pinned image on a
fresh 0700 dir with the secret as a 0600 root file answered the secret (200),
refused a wrong and the default password (401); the compiled client read the
username from nzbget.conf and reached version/status/queue/history; strict
typecheck and the module's Dockerfile build pass.

modules/nzbget/module.json

@@ -19,7 +19,7 @@
       "port": 6789,
       "protocol": "tcp",
       "from": "mesh",
-      "why": "the download client's pages"
+      "why": "the download client's pages, and the JSON-RPC API its consumers and its own tools call"
     }
   ],
   "accesses": [
@@ -35,10 +35,15 @@
       "path": "/var/lib/mesh/nzbget",
       "mode": "0700"
     },
+    {
+      "id": "state",
+      "type": "directory",
+      "mode": "0700",
+      "place": "."
+    },
     {
       "id": "config",
       "type": "directory",
-      "path": "/services/nzbget/config",
       "mode": "0700",
       "owner": "1000:1000"
     },
@@ -46,24 +51,29 @@
       "id": "server",
       "type": "container",
       "name": "nzbget",
-      "image": "lscr.io/linuxserver/nzbget@sha256:5f3d3fa71029004156eff2cbf4ef4455ce4ce59517cf13fa7d1d7c8a4cd2c8a4",
+      "image": "lscr.io/linuxserver/nzbget@sha256:ec3ef0ae7dc410084086a7fdd447deda4747531154aa1cc5c7c48ac60794e277",
       "env": {
         "PUID": "1000",
         "PGID": "1000",
-        "TZ": "Etc/UTC"
+        "TZ": "Etc/UTC",
+        "FILE__NZBGET_PASS": "/run/secrets/password"
       },
       "ports": [
         "6789"
       ],
       "volumes": [
-        "/services/nzbget/config:/config",
-        "/services/media/downloads:/downloads"
+        "${dir:config}:/config",
+        "/services/media/downloads:/downloads",
+        "/var/lib/mesh/nzbget/password:/run/secrets/password:ro"
+      ],
+      "restart-on": [
+        "needs-password"
       ]
     },
     {
       "id": "runtime-config",
       "type": "file",
-      "path": "/var/lib/mesh/nzbget/config.json",
+      "path": "${dir:state}/config.json",
       "mode": "0600",
       "content": "{}\n",
       "merge": "json"
@@ -76,22 +86,46 @@
       "volumes": [
         "/var/lib/mesh/nzbget/broker:/run/secrets/broker:ro",
         "/var/lib/mesh/nzbget/password:/run/secrets/password:ro",
-        "/var/lib/mesh/nzbget/config.json:/run/config/config.json:ro",
-        "/services/nzbget/config:/var/lib/nzbget/config:ro"
+        "${dir:state}/config.json:/run/config/config.json:ro",
+        "${dir:config}:/var/lib/nzbget/config:ro"
       ],
       "env": {
         "MESH_BROKER_FILE": "/run/secrets/broker",
-        "MESH_NZBGET_URL": "http://127.0.0.1:6789",
+        "MESH_NZBGET_URL": "http://127.0.0.1:${port:6789}",
         "MESH_NZBGET_PASSWORD_FILE": "/run/secrets/password",
         "MESH_NZBGET_CONFIG_FILE": "/run/config/config.json",
         "MESH_NZBGET_CONFIG_DIR": "/var/lib/nzbget/config"
       },
       "restart-on": [
-        "runtime-config"
+        "runtime-config",
+        "needs-password"
       ],
       "artifact": "runtime"
     }
   ],
+  "provides": [
+    "nzbget-api"
+  ],
+  "serves": {
+    "nzbget-api": {
+      "scheme": "http",
+      "port": 6789,
+      "url-base": "",
+      "username": "nzbget"
+    }
+  },
+  "requires": [
+    "route"
+  ],
+  "contributes": {
+    "route": {
+      "label": "nzbget",
+      "endpoint": "web"
+    }
+  },
+  "binds": {
+    "route": "${dir:state}/route.json"
+  },
   "build": {
     "on": [
       {