Cutover: dispatch to dogfood-lab/testing-os

The dogfood evidence store moved from mcp-tool-shop-org/dogfood-labs to
the new flagship monorepo dogfood-lab/testing-os (Wave 6 of the testing-os
migration). This workflow now dispatches to the new repo.

Old repo stays available read-only until Wave 7 archives it. Once this
PR merges, dogfood evidence from this repo lands in the new home.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: mcp-tool-shop

.github/workflows/dogfood.yml

@@ -155,7 +155,7 @@ jobs:
           echo "Submission built:"
           jq '.run_id, .overall_verdict' /tmp/submission.json
 
-      - name: Dispatch to dogfood-labs
+      - name: Dispatch to testing-os
         env:
           GH_TOKEN: ${{ secrets.DOGFOOD_TOKEN }}
         run: |
@@ -169,7 +169,7 @@ jobs:
 
           jq -n --argjson sub "$SUBMISSION" \
             '{"event_type":"dogfood_submission","client_payload":{"submission":$sub}}' \
-            | gh api repos/mcp-tool-shop-org/dogfood-labs/dispatches \
+            | gh api repos/dogfood-lab/testing-os/dispatches \
               --input - --silent
 
-          echo "Dispatched $RUN_ID to dogfood-labs"
+          echo "Dispatched $RUN_ID to testing-os"