feat(logging): show live distance & bearing when logging a contact

[patrickrb]

Problem

The Nextlog landing page promises operators "name, grid, DXCC, distance and bearing instantly" — but the logging form never actually computed distance or bearing. Worse, contacts logged through the form were persisted with a NULLdistance; only ADIF-imported QSOs ever carried the value, so form-logged contacts exported an empty <DISTANCE> field and were invisible to any distance-based stat.

Solution

Add a small, pure, client-safe Maidenhead + great-circle utility and wire it into the new-contact form.

src/lib/grid.ts (new, no server imports — safe for the browser bundle, mirroring @/lib/bands):

• gridToLatLon(grid) — centers a 4- or 6-character locator, using the exact centering ContactLocationMap already uses so the map pin and the readout agree.
• distanceKm (haversine, R=6371), bearingDeg (initial great-circle bearing, 0–360), compassPoint (16-point label), gridPath (grid→grid convenience), kmToMiles, isValidGrid.

src/app/new-contact/page.tsx:

• The Path card now shows the great-circle distance (km + mi) and bearing (degrees + compass point) from the operator's home grid to the contact. It updates live as the destination resolves — from a QRZ lookup's coordinates when available, falling back to the grid square typed into the form — and renders nothing until both endpoints resolve, so a half-typed grid never shows a bogus reading.
• The rounded distance is included in the create payload.

src/models/Contact.ts:

• Contact.create now accepts and persists distance (it was silently dropped before). The column already existed and is read by ADIF export, so form-logged contacts now round-trip a distance through export and are available to awards/stats.

Testing

• New:tests/grid.spec.ts — 15 pure-function unit tests covering grid validation, square/subsquare centering (checked against real city locations), a zero-distance and a one-degree equatorial arc (~111 km), the four cardinal bearings, compass labeling, and a known FN31→IO91 transatlantic path (~5500 km, NE).
• npm run typecheck — clean
• npm run lint — clean (no new warnings)
• npm run build — succeeds
• Re-ran the existing pure-function specs (bands, frequency-to-band) alongside the new ones — all green.

Notes / follow-up

• The "from" reference is the operator's home grid (currentUser.grid_locator), matching the Path map's origin. When no home grid is set, the readout is simply hidden.
• Backwards compatible: no schema change (the distance column already existed), no API-shape change beyond an additional optional distance field on the create body.
• Follow-up candidates: surface distance/bearing on the QuickLog dashboard card and in the edit-contact dialog, and recompute distance on grid edits.

🤖 Generated with Claude Code

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Project	Deployment	Actions	Updated (UTC)
nodelog	Ready	Preview, Comment	Jul 23, 2026 11:10pm