ci: derive image name + package linking from repo, add link step

Both workflows had a static IMAGE env (<owner>/<product>-docs-mcp)
and a static --package arg in the GC step. Switch both to Gitea
Actions context variables so a clone of the template into any repo
name works on the first CI run without find/replace:

  IMAGE: ${{ github.repository_owner }}/${{ github.event.repository.name }}
  --owner ${{ github.repository_owner }}
  --package ${{ github.event.repository.name }}

Also add the "Link container package to this repo" step that was
missing from the template (and which, naively copy-pasted from the
reference build, would have linked everything back to docs-mcp-
template). The new step derives owner + package + link-target all
from the running repo's context.

The github.* namespace is Gitea Actions' inherited GitHub-Actions
context — values come from the Gitea server, not github.com. Same
mechanism the reference build's $GITHUB_SHA tag-builder uses.

CLAUDE.md updated to note that image and package naming are
repo-derived; only registry endpoints and the Ollama URL need
per-clone editing.

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

.gitea/workflows/image-only.yml

@@ -16,7 +16,11 @@ on:
 env:
   REGISTRY_PUSH: <lan-host>:<port>
   REGISTRY_PULL: <public-registry-hostname>
-  IMAGE: <owner>/<product>-docs-mcp
+  # Image name derives from the actual repo at runtime, so a clone
+  # doesn't need to find/replace anything. e.g. justin/my-product-docs.
+  # github.* context is Gitea Actions' inherited GitHub-Actions namespace
+  # — values come from the Gitea server, not github.com.
+  IMAGE: ${{ github.repository_owner }}/${{ github.event.repository.name }}
   OLLAMA_URL: http://<gpu-host>:11434
   EMBED_MODEL: nomic-embed-text
   PRODUCT_NAME: <product>
@@ -63,7 +67,7 @@ jobs:
         run: python -m rag.index --rebuild
 
       - name: Log in to registry (LAN endpoint)
-        run: echo "${{ secrets.REGISTRY_TOKEN }}" | docker login "${REGISTRY_PUSH}" -u <user> --password-stdin
+        run: echo "${{ secrets.REGISTRY_TOKEN }}" | docker login "${REGISTRY_PUSH}" -u "${{ github.repository_owner }}" --password-stdin
 
       - name: Build & push image
         run: |
@@ -78,12 +82,34 @@ jobs:
           docker push "${REGISTRY_PUSH}/${IMAGE}:${SHA_TAG}"
           docker push "${REGISTRY_PUSH}/${IMAGE}:${DATE_TAG}"
 
+      - name: Link container package to this repo
+        # Gitea container packages are owned by a USER, not a repo —
+        # they don't auto-appear under the repo's Packages tab.
+        # This API call creates the association. One-time-effective:
+        # re-running returns 400 once linked, which we swallow.
+        # Endpoint requires Gitea 1.21+.
+        env:
+          GITEA_TOKEN: ${{ secrets.REGISTRY_TOKEN }}
+        run: |
+          OWNER="${{ github.repository_owner }}"
+          PKG="${{ github.event.repository.name }}"
+          BODY=$(mktemp)
+          CODE=$(curl -sS -o "$BODY" -w "%{http_code}" -X POST \
+            -H "Authorization: token ${GITEA_TOKEN}" \
+            "https://${REGISTRY_PULL}/api/v1/packages/${OWNER}/container/${PKG}/-/link/${PKG}")
+          echo "link http=$CODE  body=$(cat "$BODY")"
+          case "$CODE" in
+            201) echo "linked package to ${OWNER}/${PKG}" ;;
+            400) echo "already linked (re-link returns 400) — ok" ;;
+            *)   echo "unexpected status $CODE"; exit 1 ;;
+          esac
+
       - name: Prune old container versions
         env:
           GITEA_TOKEN: ${{ secrets.REGISTRY_TOKEN }}
         run: |
           python scripts/registry_gc.py \
-            --owner <user> \
-            --package <product>-docs-mcp \
+            --owner "${{ github.repository_owner }}" \
+            --package "${{ github.event.repository.name }}" \
             --keep-days 90 \
             --keep-latest 5