Feature: auto-open GitHub issues from meeting note action items

Problem

Every meeting note in docs/meeting_notes/ ends with an Action items section assigning tasks to specific committee members. But these are plain RST text there is no tracking, no visibility, and no way to know what's outstanding without reading every note manually.

"Upload meeting notes to repo" appears in September, October, and December 2025 notes carried over three months with no way to see it was still open.

The committee already uses GitHub issues as the primary tracker for infrastructure requests. Their own internal action items should live there too.

Proposed solution

A workflow that triggers whenever a meeting note is pushed to main and automatically opens one GitHub issue per action item found in the Action items section labeled action-item + meeting-notes, with the date, assignee, and a link back to the source note in the body.

Duplicate detection prevents re-opening if the same note is pushed again.
Nothing is auto-closed that stays a human decision.

Meeting note format (consistent across all 2024–2025 notes)

Action items
============

- Do the thing **Firstname Lastname**
- Another task **Someone Else**

Start by reviewing the consistent Action items sections in docs/meeting_notes/ and the proposed workflow trigger on pushes to main. Define how the workflow extracts the task, assignee, date, and source-note link, then handles duplicate detection. Done means one labeled issue per new action item, no duplicate issue on repeated pushes, and no automatic closing.