fix: add Bash tool and simplify Claude prompt for skill execution (#93)

* fix: update all GitHub Actions to latest versions for Node.js 24 full support

- Update actions/checkout from v4.2.2 to v7.0.1
- Update google-github-actions/auth from v2.1.4 to v3.0.0

These versions are fully compatible with Node.js 24 and eliminate all
deprecation warnings in workflow logs.

* fix: enable GCP credential file and environment variables for Claude access

Claude needs access to GCP credentials to authenticate with Vertex API.
Changed:
- create_credentials_file: true (was false)
- export_environment_variables: true (was false)

This allows the google-github-actions/auth action to create the credential
file and set GOOGLE_APPLICATION_CREDENTIALS so Claude can access it.

* fix: move PR data file to working directory for Claude access

Claude can only access files within the job's working directory
(/home/runner/work/hyperfleet-claude-plugins/hyperfleet-claude-plugins).

Changed data file location from /tmp/pr-data.json to pr-data.json.

* fix: add Bash tool and simplify Claude prompt for skill execution

The /open-prs skill needs Bash access to run jq pipelines.
Updated prompt to invoke the skill directly rather than giving step-by-step instructions.

Author: rafabene

.github/workflows/open-prs-digest.yml

@@ -108,12 +108,11 @@ jobs:
         id: claude
         with:
           use_vertex: "true"
-          prompt: |
-            Process the collected PR data from pr-data.json.
-            Follow SKILL.md instructions: pipe through score.jq,
-            classify Factor 4 for each PR, then pipe through format-output.jq with --arg mode slack.
-            Output ONLY the final Slack mrkdwn content — no surrounding explanation or code blocks.
-          claude_args: "--append-system-prompt-file ./hyperfleet-work-triage/skills/open-prs/SKILL.md.resolved --allowedTools Read,Glob,Grep --model claude-haiku-4-5@20251001"
+           prompt: |
+             Execute the /open-prs skill to process PR data and return formatted Slack output.
+             The collected PR data is in pr-data.json.
+             Output ONLY the final Slack mrkdwn content — no surrounding explanation or code blocks.
+          claude_args: "--append-system-prompt-file ./hyperfleet-work-triage/skills/open-prs/SKILL.md.resolved --allowedTools Read,Glob,Grep,Bash --model claude-haiku-4-5@20251001"
         env:
           ANTHROPIC_VERTEX_PROJECT_ID: ${{ secrets.ANTHROPIC_VERTEX_PROJECT_ID }}
           CLOUD_ML_REGION: global