- add util.Go with panic recovery for background goroutines
- add util.EscapeLike and explicit ESCAPE clause for SQL LIKE queries
- add DummyCheckPassword and subtle.ConstantTimeCompare against timing attacks
- enforce session ID rotation upon login/oauth callback to prevent session fixation
- add sliding window login failure rate limiting and oauth state rate limiting
- fix redis client capture race in pubsub listeners and wait on stop channel
- adjust global --primary to oklch(51.1% 0.262 276.966) for WCAG AA contrast
- fix semantic heading levels and missing aria-labels across UI components
- document security, concurrency, and a11y standards in AGENTS.md
- Update sidebar active menu button text color to use theme dynamic `sidebar-primary` variable instead of hardcoded hex value.
- Add missing `destructive-foreground` variables to default theme config and styles, resolving the black-on-black text contrast issue on confirmation dialog delete buttons.
- Update changelog to track these fixes.
ryan