feat(workflow): add grace-period-minutes input to auto-close workflow

[Sachindu-Nethmin]

Description

Adds a grace_period_minutes workflow dispatch input to the auto-close workflow, allowing users to manually specify a grace period in minutes. Once the grace period expires, issues labelled potential-duplicate are automatically labelled duplicate and closed.

Also fixes a 403 permission error that occurred when GH_PAT was set but lacked issues:write scope — the workflow now uses the built-in github.token which already has the correct permissions via the permissions block.

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to change)
• 📚 Documentation update
• 🔧 Configuration/build change
• ♻️ Refactoring (no functional changes)
• 🧪 Test update

Related Issues

Relates to #12

Changes Made

• Added grace_period_minutes input to workflow_dispatch in auto-close.yml — accepts a number of minutes; leave empty to use the configured default (72 h)
• Passes --grace-period-minutes flag to the CLI when the input is set
• Replaced secrets.GH_PAT with github.token to fix 403 errors caused by an under-scoped PAT; the workflow permissions: issues: write block already grants the built-in token everything it needs

Testing

• I have run go build ./... successfully
• I have run go test ./... successfully
• I have run go vet ./... successfully
• I have tested the changes locally

Manually triggered the workflow with grace_period_minutes=1 — issues #15 and #16 were successfully labelled duplicate and closed within seconds.

Screenshots (if applicable)

Workflow run output:

{
  "processed": 3,
  "closed": 2,
  "skipped_grace_period": 0,
  "skipped_human_activity": 1,
  "details": [
    {
      "number": 16,
      "action": "closed",
      "reason": "grace period expired, no human activity"
    },
    {
      "number": 15,
      "action": "closed",
      "reason": "grace period expired, no human activity"
    },
    {
      "number": 3,
      "action": "skipped_human",
      "reason": "human activity detected after label was applied"
    }
  ]
}

Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• New and existing unit tests pass locally with my changes

Additional Notes

The grace_period_minutes input overrides the grace_period_hours value in .github/simili.yaml for that specific run only. The daily scheduled run continues to use the config file value.