* fix: CSV column name mismatches in data loading
- sect.py: Fix headquarter_name/headquarter_desc -> name/desc when reading sect_region.csv
- sect.py: Move sid initialization before technique lookup to fix unbound variable bug
- technique.py: Change sect (name) to sect_id (int) to match technique.csv column
- elixir.py: Remove redundant get_int(row, "id") that reads non-existent column
These fixes ensure:
1. Sect headquarters display correct location names (e.g., "大千光极城" instead of "不夜城")
2. Sect techniques are correctly associated and displayed
3. Technique sect restrictions work properly
* fix: update main.py to use sect_id, add CSV loading tests
- main.py: Change technique.sect to technique.sect_id in API response
- Add tests/test_csv_loading.py to verify CSV column names match code
* test: add API test for /api/meta/game_data endpoint
Verify that techniques in API response use sect_id field (not sect)
* fix: add None check for hq_region in AvatarFactory
Remove redundant code that adds sect headquarters to known_regions.
This logic is already handled by Avatar._init_known_regions() which
uses sect_id matching (more reliable than name-based lookup).
The removed code was causing a flaky test (~1% failure rate) because
resolve_query returns None in test environments with simplified maps.
