fix: put the settings card on the Plugins page with a browser half

The `volatile()` markers made the Host serve the namespace, and that was as
far as it went: the Plugins page does not build a card from a `Config` schema.
It draws only what browser halves register into the slots it declares, which is
why dsh-slopo, dsh-recall and dsh-context all ship a `client/` — and why this
plugin, with two served fields, still showed nothing.

The card registers into `plugins.bundle.config` while
`configForms.whileServed` reports the namespace served. The two keys are
deliberately different strings and that is the trap in the file: the settings
document is filed under the profile entry id (`facet-policy`) while the card is
keyed by the package name (`dsh-facet`). Every sibling plugin happens to name
them identically. Binding the form to the wrong one yields a card that renders,
saves, and writes nowhere, so `test/client.test.js` pins both, holds the card's
field list to the schema's volatile fields, and refuses to register at all when
the namespace is not served.

package.json

@@ -14,6 +14,9 @@
       "types": "./lib/types/guard.d.ts",
       "default": "./lib/guard.js"
     },
+    "./client": {
+      "default": "./client/client.js"
+    },
     "./cordis.patch.yml": "./cordis.patch.yml",
     "./presets/facet.patch.yml": "./presets/facet.patch.yml",
     "./package.json": "./package.json"
@@ -21,6 +24,7 @@
   "files": [
     "index.js",
     "lib",
+    "client",
     "presets",
     "cordis.patch.yml",
     "README.md"
@@ -40,6 +44,13 @@
         "./cordis.patch.yml",
         "./presets/facet.patch.yml"
       ]
+    },
+    "client": {
+      "platform": "web",
+      "inject": [
+        "@deepseek-ai/dsh-client-ui-settings",
+        "@deepseek-ai/dsh-client-ui-plugin-manager"
+      ]
     }
   },
   "keywords": [