## Summary
Milestone 4 of #482: adds affinity-aware hop resolution to improve
disambiguation accuracy across all hop resolution in the app.
### What changed
**Backend — `prefixMap.resolveWithContext()` (store.go)**
New method that applies a 4-tier disambiguation priority when multiple
nodes match a hop prefix:
| Priority | Strategy | When it wins |
|----------|----------|-------------|
| 1 | **Affinity graph score** | Neighbor graph has data, score ratio ≥
3× runner-up |
| 2 | **Geographic proximity** | Context nodes have GPS, pick closest
candidate |
| 3 | **GPS preference** | At least one candidate has coordinates |
| 4 | **First match** | No signal — current naive fallback |
The existing `resolve()` method is unchanged for backward compatibility.
New callers that have context (originator, observer, adjacent hops) can
use `resolveWithContext()` for better results.
**API — `handleResolveHops` (routes.go)**
Enhanced `/api/resolve-hops` endpoint:
- New query params: `from_node`, `observer` — provide context for
affinity scoring
- New response fields on `HopCandidate`: `affinityScore` (float,
0.0–1.0)
- New response fields on `HopResolution`: `bestCandidate` (pubkey when
confident), `confidence` (one of `unique_prefix`, `neighbor_affinity`,
`ambiguous`)
- Backward compatible: without context params, behavior is identical to
before (just adds `confidence` field)
**Types (types.go)**
- `HopCandidate.AffinityScore *float64`
- `HopResolution.BestCandidate *string`
- `HopResolution.Confidence string`
### Tests
- 7 unit tests for `resolveWithContext` covering all 4 priority tiers +
edge cases
- 2 unit tests for `geoDistApprox`
- 4 API tests for enhanced `/api/resolve-hops` response shape
- All existing tests pass (no regressions)
### Impact
This improves ALL hop resolution across the app — analytics, route
display, subpath analysis, and any future feature that resolves hop
prefixes. The affinity graph (from M1/M2) now feeds directly into
disambiguation decisions.
Part of #482
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Co-authored-by: you <you@example.com>