12B v3 manifest: register the verify role

tiered-v3/gemma4_12b_qat_decode_int4linsym_hf16_msdpa_g8_wkv_stable_pf64_tiered_c4k_c8k_c16k_c32k_c64k_c128k_c256k/metadata.json

@@ -28,6 +28,9 @@
         "prefill_c65536",
         "prefill_c131072",
         "prefill_c262144"
+      ],
+      "verify": [
+        "verify_c262144"
       ]
     },
     "capacity_tiers": [