Remove direction bars and fix sunset arrival guidance

[aeharding]

Sunset guidance now opens when estimated arrival reaches 30 minutes before sunset or later. A flight can show its sunset margin while sunset is still hours away. Without an available arrival estimate, the existing current-time window applies, and guidance still expires one hour after sunset. Replay diagnostics use the same display gate as live flight.

Remove the green screen-edge direction bars and their unused acquisition logic. The existing direction instrument remains. Three-digit sunset countdowns fit beside duration by widening the right instrument column, with unchanged type size and row height.

Replace the simplified sunrise equation with local Meeus/NOAA solar-position and equation-of-time calculations, iterated at each rise/set event. Fourteen independent USNO date/location fixtures now require sunrise and sunset to round to the published minute; the former sunset calculation differed by up to 83 seconds from those published values, versus 26 seconds with the new calculation. Absolute clock labels also round to the nearest minute.

The FAA directs pilots to USNO calculated tables. These calculations use the standard upper-limb horizon and refraction; terrain and pilot altitude are not inputs. Reference queries are recorded with the fixtures and are never called by the app.

Validation:

• TypeScript, ESLint with zero warnings, formatting, CSS conventions, and production build pass.
• 554 unit tests pass, including arrival thresholds, post-sunset arrivals, replay/live agreement, and USNO references.
• Browser tests cover early arrival guidance, absent direction bars, and overflow across portrait phones, landscape phones, and tablets. Compiled production CSS was also checked at those sizes.
• Full Playwright suite: 108 pass, 10 sync tests skip without local CouchDB. Run with two workers after the six-worker run timed out in replay/camera tests; both pass in the completed run.