End-to-end CVE history support and hardens loading/startup

- Added end-to-end cvehist support: DB table/migration, models, loader, CLI search, and /api/search/cvehist.
- Extended search filters for CVE history: CVE ID, change dates, change-event, and change-type.
- Hardened loading: upserts for CVE/CPE/history, timeouts, resume support, and cleaner EPSS sync/error handling.
- Improved startup: DB schema migration now runs automatically before the web app starts.
- Updated config/docs for the CVE history API and new load/search commands.

Fix for #22

fix: correct conditional logic for version search options

Add search options for CPE/CVE: version-start and version-end

Update the context.py and allow ENV NAME in Dockerfile

Typo fixes from previous commit

Avoiding empty attributes from CVE search result's

Fix search on CVE id only from prev change