Enhance Meetup sync: merge iCal with past events, improve parsing, update workflow triggers, and add tests

[carloshvp]

Motivation

• Ensure the Meetup sync gathers recent historical events missing from the iCal feed and make parsing more robust for real-world Meetup HTML/JSON-LD shapes.
• Prevent the Actions job from committing changes during pull requests while still running syncs on PRs for validation.

Description

• Update GitHub Actions workflow to also run on pull_request and to only commit changes when the event was triggered by push, schedule, or workflow_dispatch, and update README to document trigger and a new MEETUP_PAST_EVENTS_URL option.
• Add DEFAULT_PAST_EVENTS_URL, unescape_ical_text, and unescape ical fields in parse_ical_events to correctly handle escaped line breaks and characters from iCal.
• Extend parse_ld_json_events to expand @graph nodes and parse richer JSON-LD shapes, and add merge_events to deduplicate and combine multiple sources.
• Add HTML helpers extract_event_urls_from_html and fetch_url and update fetch_events to first try iCal, then pull recent past events from the events/past page (including individual event pages for details), merge results, and fall back to the main events page as needed.
• Add unit tests in tests/test_sync_meetup_events.py covering relative/absolute event link extraction and JSON-LD @graph node parsing.

Testing

• Ran the unit tests with python -m unittest tests/test_sync_meetup_events.py and both tests passed.
• The updated workflow was validated locally by inspecting trigger logic and README updates were applied to reflect new behavior.

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[chatgpt-codex-connector]

Continue fallback to events page when iCal data is unavailable

Returning immediately on merged_events skips the /events/ fallback path whenever events/past has any data. In the scenario where the iCal source is down or empty but events/past succeeds, this function returns only past events and never fetches upcoming events from MEETUP_EVENTS_URL, so the site can silently lose all upcoming listings during an iCal outage. Only short-circuit here when iCal data is present, or merge in /events/ results before returning.

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