chore: migrate workflows from claude-code-base-action to claude-code-action

Updates GitHub workflow files to use the new claude-code-action@v1 and replaces prompt_file with inline prompt parameter.

Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Generated-By: Claude Code (cli/claude-opus-4-5=100%)
Claude-Steers: 3
Claude-Permission-Prompts: 4
Claude-Escapes: 0

.github/workflows/claude-dedupe-issues.yml

@@ -23,7 +23,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Run Claude Code slash command
-        uses: anthropics/claude-code-base-action@v1
+        uses: anthropics/claude-code-action@v1
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with: