Record pending OpenCode 1.18.18 image

Allow public_ci rows that the upstream recorder already emits as pending,
and add v1.18.18 as an uncertified shared-client target. Certified alpha8
rows and consumer tuples stay as they are.

manifests/image-matrix.json

@@ -102,6 +102,17 @@
         "full_text": "compat-ok",
         "llm_request_count": 1
       }
+    },
+    {
+      "id": "upstream-1.18.18-f3e00f8e25500150373c817e24b13f2f08e2ccd4cafd53dc3ad4827d47863b6f",
+      "version": "1.18.18",
+      "image": "ghcr.io/anomalyco/opencode@sha256:f3e00f8e25500150373c817e24b13f2f08e2ccd4cafd53dc3ad4827d47863b6f",
+      "tag_provenance": "ghcr.io/anomalyco/opencode:1.18.18",
+      "consumers": [],
+      "profiles": ["ruby-rest-sse"],
+      "required_consumer_profiles": [],
+      "certification_scope": "shared-client-contract-only",
+      "certification_status": "pending"
     }
   ],
   "host_canary": [