v0.2.4

Added

• oikb validate command — validate .oikb.yaml without running syncs.
• --concurrency flag for oikb sync — opt-in parallel uploads (also configurable per-entry in .oikb.yaml).
• Upload retry with exponential backoff — transient 5xx errors retry up to 3 times.

Fixed

• Daemon now applies filter.include/filter.exclude from .oikb.yaml (previously silently ignored).
• Connector HTTP clients are now properly closed after sync completes.
• GitHub connector caches default branch lookup — eliminates redundant API calls per file.

Changed

• Removed 30+ no-op optional dependencies from pyproject.toml ([github], [confluence], etc.) that just re-declared httpx (already a core dep). Only extras with real dependencies remain: s3, gcs, azure, dropbox, r2, gdrive, gmail, gsites, web, oracle.