Address Gadfly review findings on build-image CI

Workflow:
- Pass untrusted github.ref_name/repository/sha/token via env instead of
  inline ${{ }} in run: blocks, closing a branch-name shell-injection vector.
- Check out the exact triggering commit (fetch by SHA, branch fallback) so
  the sha-<short> tag matches what was built.
- Guard the tag scheme: a non-main branch named/sanitized to "latest" can't
  clobber :latest, and an empty sanitized name falls back to branch-<sha>.
- Build --tag flags as a bash array (no word-splitting), drop the
  comma-string round-trip, and check-then-create the buildx builder so a
  real failure isn't swallowed.

Dockerfile:
- GOWORK=off in the build stage (matches the Makefile convention).
- npm ci uses a BuildKit cache mount.
- Drop the stale issue-number reference in a comment.

.dockerignore:
- Add .env/.env.*, go.work/go.work.sum, web/.vite; drop nonexistent .github.

Graded all findings in the gadfly store. Deferred/keep-as-is: token-in-clone-URL
(Gitea masks the secret in logs), sanitization collisions across branch names
(the sha-<short> tag is the collision-proof identifier), and registry build
cache (current builds are fast). False positives: alpine ships wget (busybox);
docker login is its own step.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01JdQpdYYsTgtkJBxbcpAszi

.gitea/workflows/build-image.yml

@@ -1,7 +1,7 @@
 name: Build image
 
 # Build the single-binary image and push it to the Gitea container registry so
-# it can be deployed with Komodo. Tagging:
+# it can be deployed with Komodo. Tagging (see README for the canonical table):
 #   * main            -> :latest
 #   * any other branch -> :<branch-name>   (sanitized to valid Docker tag chars)
 #   * every build also -> :sha-<short>      (immutable, handy for pinning)
@@ -27,12 +27,27 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
+        # Untrusted values (branch name) go through env, never inline ${{ }}, so a
+        # crafted branch name can't inject shell. Check out the exact triggering
+        # commit so the sha-<short> tag matches the code that was built.
+        env:
+          REPO: ${{ github.repository }}
+          REF_NAME: ${{ github.ref_name }}
+          SHA: ${{ github.sha }}
+          GIT_TOKEN: ${{ github.token }}
         run: |
-          REPO_URL="https://token:${{ github.token }}@gitea.stevedudenhoeffer.com/${{ github.repository }}.git"
-          git clone --depth=1 --branch "${{ github.ref_name }}" "$REPO_URL" .
+          git init -q .
+          git remote add origin "https://token:${GIT_TOKEN}@gitea.stevedudenhoeffer.com/${REPO}.git"
+          git fetch -q --depth=1 origin "$SHA" || git fetch -q --depth=1 origin "$REF_NAME"
+          git checkout -q FETCH_HEAD
 
       - name: Set up Docker Buildx
-        run: docker buildx create --use --name pansy-builder --driver docker-container 2>/dev/null || docker buildx use pansy-builder
+        # Check first so a genuine create failure surfaces (rather than being
+        # hidden behind a swallowed "already exists").
+        run: |
+          docker buildx inspect pansy-builder >/dev/null 2>&1 \
+            || docker buildx create --name pansy-builder --driver docker-container
+          docker buildx use pansy-builder
 
       - name: Log in to Gitea registry
         env:
@@ -40,34 +55,33 @@ jobs:
           REGISTRY_PASSWORD: ${{ secrets.REGISTRY_PASSWORD }}
         run: echo "${REGISTRY_PASSWORD}" | docker login gitea.stevedudenhoeffer.com -u "${REGISTRY_USER}" --password-stdin
 
-      - name: Compute tags
-        id: meta
+      - name: Build and push (linux/amd64)
+        env:
+          REF_NAME: ${{ github.ref_name }}
+          SHA: ${{ github.sha }}
         run: |
-          SHA_SHORT=$(echo "${GITHUB_SHA}" | cut -c1-7)
-          if [ "${GITHUB_REF_NAME}" = "main" ]; then
+          SHA_SHORT=$(echo "$SHA" | cut -c1-7)
+
+          if [ "$REF_NAME" = "main" ]; then
             PRIMARY="latest"
           else
             # Normalize the branch name to valid Docker tag chars [a-zA-Z0-9._-].
-            PRIMARY=$(echo "${GITHUB_REF_NAME}" | sed 's/[^a-zA-Z0-9._-]/-/g' | sed 's/--*/-/g' | sed 's/^[-.]*//;s/-$//')
+            PRIMARY=$(echo "$REF_NAME" | sed 's/[^a-zA-Z0-9._-]/-/g; s/--*/-/g; s/^[-.]*//; s/-*$//')
+            # A non-main branch must never clobber :latest, and the tag can't be empty.
+            [ "$PRIMARY" = "latest" ] && PRIMARY="branch-latest"
+            [ -z "$PRIMARY" ] && PRIMARY="branch-${SHA_SHORT}"
           fi
-          TAGS="${IMAGE_NAME}:${PRIMARY},${IMAGE_NAME}:sha-${SHA_SHORT}"
-          echo "tags=${TAGS}" >> "$GITHUB_OUTPUT"
-          echo "Building tags: ${TAGS}"
 
-      - name: Build and push (linux/amd64)
-        run: |
-          TAG_FLAGS=""
-          IFS=',' read -ra TAG_ARRAY <<< "${{ steps.meta.outputs.tags }}"
-          for tag in "${TAG_ARRAY[@]}"; do
-            TAG_FLAGS="$TAG_FLAGS --tag $tag"
-          done
+          # Build the tag flags as an array so no word-splitting/quoting surprises.
+          TAGS=(--tag "${IMAGE_NAME}:${PRIMARY}" --tag "${IMAGE_NAME}:sha-${SHA_SHORT}")
+          echo "Building ${IMAGE_NAME}:${PRIMARY} and ${IMAGE_NAME}:sha-${SHA_SHORT}"
 
           docker buildx build \
             --push \
             --platform linux/amd64 \
-            $TAG_FLAGS \
-            --build-arg "BUILD_COMMIT=${GITHUB_SHA}" \
-            --build-arg "BUILD_BRANCH=${GITHUB_REF_NAME}" \
+            "${TAGS[@]}" \
+            --build-arg "BUILD_COMMIT=${SHA}" \
+            --build-arg "BUILD_BRANCH=${REF_NAME}" \
             --build-arg "BUILD_TIME=$(date -u '+%Y-%m-%dT%H:%M:%SZ')" \
             --file ./Dockerfile \
             .