Adds `nib tui` command and `make tui` target. Scrollable entity list
with j/k navigation, enter for detail view, `a` to capture new entries
using the existing parse grammar, and `d` to delete.
- Add rows.Err() checks after all scan loops (entities, tags, resolve)
- Surface time.Parse errors instead of silently discarding
- Extract entityRow scan helper to eliminate Get/List duplication
- Cap request body at 1MB via MaxBytesReader
- Stop leaking internal errors to API clients (log server-side only)
- Block javascript: URIs in link card open button (XSS)
- Fix all go vet failures in api_test.go (unchecked http errors)
- Add tests for display package, generateCardData, absorb-source-card
- Run go mod tidy to fix direct/indirect dep markers
lerko