Add adobe-for-creativity plugin

Adobe's Creative Cloud skills for image editing, design automation,
background removal, vectorization, and retouching. Points at the
plugins/creative-cloud/adobe-for-creativity subdir of adobe/skills.

.claude-plugin/marketplace.json

@@ -524,9 +524,9 @@
       "category": "productivity",
       "source": {
         "source": "url",
-        "url": "https://github.com/coderabbitai/skills.git"
+        "url": "https://github.com/coderabbitai/claude-plugin.git"
       },
-      "homepage": "https://github.com/coderabbitai/skills"
+      "homepage": "https://github.com/coderabbitai/claude-plugin.git"
     },
     {
       "name": "commit-commands",

.github/workflows/validate-frontmatter.yml

@@ -9,10 +9,6 @@ on:
 
 jobs:
   validate:
-    # Fork PRs are auto-closed by close-external-prs.yml, so skip validation
-    # for them entirely. This also prevents untrusted filenames from forks
-    # from ever reaching the shell steps below.
-    if: github.event.pull_request.head.repo.full_name == github.repository
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -24,19 +20,16 @@ jobs:
 
       - name: Get changed frontmatter files
         id: changed
-        env:
-          GH_TOKEN: ${{ github.token }}
-          PR_NUMBER: ${{ github.event.pull_request.number }}
         run: |
           # Use diff-filter=AMRC to exclude deleted files (D) - only Added, Modified, Renamed, Copied
-          FILES=$(gh pr diff "$PR_NUMBER" --name-only --diff-filter=AMRC | grep -E '(agents/.*\.md|skills/.*/SKILL\.md|commands/.*\.md)$' || true)
+          FILES=$(gh pr diff ${{ github.event.pull_request.number }} --name-only --diff-filter=AMRC | grep -E '(agents/.*\.md|skills/.*/SKILL\.md|commands/.*\.md)$' || true)
           echo "files<<EOF" >> "$GITHUB_OUTPUT"
           echo "$FILES" >> "$GITHUB_OUTPUT"
           echo "EOF" >> "$GITHUB_OUTPUT"
+        env:
+          GH_TOKEN: ${{ github.token }}
 
       - name: Validate frontmatter
         if: steps.changed.outputs.files != ''
-        env:
-          FILES: ${{ steps.changed.outputs.files }}
         run: |
-          printf '%s\n' "$FILES" | xargs bun .github/scripts/validate-frontmatter.ts
+          echo "${{ steps.changed.outputs.files }}" | xargs bun .github/scripts/validate-frontmatter.ts