[Bug] No automated tests cover region detection, dedup, or date parsing

[Infrasity-Labs]

Bug Description

There's no tests/ directory or test runner anywhere in the repo, despite fetchers/config.py (determine_region, deduplicate_events, parse_date) and checks/parse_readme.py (parse_date, parse_readme) containing exactly the kind of fiddly string logic that regresses silently, as shown by the substring-dedup and escaped-pipe bugs already filed against this repo.

Link to the Conference (if applicable)

Not applicable, this is about test coverage for the shared parsing and classification logic, not a specific listing.

Expected Behavior

The core logic used to classify and dedupe events should have test coverage so a regression gets caught before it reaches main.

Additional Context

Suggested fix: add a tests/ directory with pytest covering:

• determine_region(): a handful of city and country strings per continent, plus the "unknown location gets rescued from name or link" path for virtual events.
• deduplicate_events(): same series in a different city should not be treated as a duplicate; the same event with a slightly reworded name but the same date and location should be.
• parse_readme.parse_date(): both ISO dates and month-name formats.

Where to look: fetchers/config.py, checks/parse_readme.py.

Acceptance criteria:

• tests/test_config.py and tests/test_parse_readme.py exist and pass with pytest.
• All three behaviors above are covered.