DuckDB has used WAL by default since v0.8, so this pragma is not
valid DuckDB syntax. Removed obsolete try-except block that attempted
to enable WAL on system database initialization.
- New extract_init.py: creates extract.duckdb with _meta + views for 6 entity types
- Update default paths to /data/extracts/jira/data/ and /data/extracts/jira/raw/
- After parquet writes, update _meta table in extract.duckdb
- Trigger SyncOrchestrator.rebuild_source("jira") after successful transform