Fix (Waypoints): clear placeholder results on panel close (#365)

[AaravJalan]

🛠️ Fixes Issue

Closes #365

When the directions panel was closed and reopened, waypoints that were in a loading/placeholder state (coordinate pinned on map, reverse geocode still in flight, or just completed) would re-render with stale data — making it appear as if a waypoint had been populated when the user hadn't finished setting one.

👨‍💻 Changes proposed

src/stores/directions-store.ts

• Added clearPlaceholderWaypoints action to DirectionsActions interface
• Implemented the action: iterates waypoints and clears any that contain only placeholder geocode results (those with empty title), resetting both geocodeResults and userInput to empty

src/components/route-planner.tsx

• Call clearPlaceholderWaypoints() before toggleDirections() on sheet close, so placeholder state is always cleaned up when the panel is dismissed

src/components/directions/waypoints/waypoint-item.tsx

• Look up waypoint by id instead of index to prevent stale index references from causing wrong data to render after array mutations

Type of Change

• Bug fix

[github-actions]

Preview is ready! 🚀 You can view it here: https://valhalla-app-tests.gis-ops.com/399

[AaravJalan]

GSOC Contribution