Use real H7 centroids from API — remove spiral approximation

src/screens/Map.jsx

@@ -2,11 +2,18 @@ import { useState, useEffect } from 'react'
 import { WAYPOINTS, ROUTES } from '../constants.js'
 import { fetchMapCells } from '../api.js'
 
-// Bounding box — Mediterranean basin
 const BBOX = { minLng: 5, maxLng: 38, minLat: 28, maxLat: 48 }
 const W = 800
 const H = 460
 
+const H5_IDS = {
+  ostia:       '851e805bfffffff',
+  capua:       '851e8333fffffff',
+  brundisium:  '851e8ba3fffffff',
+  carthago:    '85386e23fffffff',
+  alexandria:  '853f5ba7fffffff',
+}
+
 // H3 res-5 cell centre coordinates — hardcoded, h3-js not in browser bundle
 const CENTRES = {
   ostia:       { lat: 41.73, lng: 12.23 },
@@ -16,62 +23,29 @@ const CENTRES = {
   alexandria:  { lat: 31.20, lng: 29.92 },
 }
 
-// H3 res-5 hex string IDs — used for API calls
-const H5_IDS = {
-  ostia:       '851e805bfffffff',
-  capua:       '851e8333fffffff',
-  brundisium:  '851e8ba3fffffff',
-  carthago:    '85386e23fffffff',
-  alexandria:  '853f5ba7fffffff',
-}
-
 const WAYPOINT_IDS = ['ostia', 'capua', 'brundisium', 'carthago', 'alexandria']
 const ROUTE_ORDER  = ['olive', 'wine', 'grain', 'linen']
-
-// Active epoch — Roman period for OTIVM-II
-// sl_offset_cm = -10 (effectively zero). Coastline matches modern sea level.
 const EPOCH        = 'roman_14bce'
 
+// H7 cell approximate radius in SVG pixels — H7 inradius ~10km
+// At our projection (33° = 800px wide), 1° lng ≈ 24px, 10km ≈ 9px
+const H7_RADIUS = 9
+
 function project(lat, lng) {
   const x = ((lng - BBOX.minLng) / (BBOX.maxLng - BBOX.minLng)) * W
   const y = ((BBOX.maxLat - lat) / (BBOX.maxLat - BBOX.minLat)) * H
   return { x, y }
 }
 
-// Approximate H7 cell position within its H5 parent using a sunflower spiral.
-// H7 cells are rendered as circles — exact hex geometry requires h3-js (server-side only).
-// The spiral distributes 49 cells across the H5 area. Visual approximation only.
-// Will be replaced when the API returns per-cell centroids.
-function h7ApproxPos(h5Id, cellIndex) {
-  const cx = CENTRES[h5Id]
-  if (!cx) return null
-  const { x: cx_px, y: cy_px } = project(cx.lat, cx.lng)
-  // Golden angle spiral — distributes points evenly across H5 area (~90km)
-  // At our projection scale, H5 spans ~120px. Space cells ~16px apart.
-  const SPACING = 14
-  const angle = cellIndex * 2.399963 // golden angle radians
-  const radius = SPACING * Math.sqrt(cellIndex)
-  return {
-    x: cx_px + Math.cos(angle) * radius,
-    y: cy_px + Math.sin(angle) * radius,
-  }
-}
-
-const H7_RADIUS = 8
-
 export default function Map({ state }) {
   const chapter = state?.chapter ?? 1
   const [cellData, setCellData] = useState({})
 
-  // Fetch H7 cells for all revealed waypoints.
-  // A waypoint is revealed when chapter >= waypoint.chapter.
-  // Ostia (chapter 1) is revealed from the start.
-  // Cells are fetched once per waypoint and cached in state.
   useEffect(() => {
     WAYPOINT_IDS.forEach((id) => {
       const wp = WAYPOINTS[id]
-      if (chapter < wp.chapter) return   // not yet revealed
-      if (cellData[id]) return            // already loaded
+      if (chapter < wp.chapter) return
+      if (cellData[id]) return
       fetchMapCells(H5_IDS[id], EPOCH).then(data => {
         if (data?.cells) {
           setCellData(prev => ({ ...prev, [id]: data.cells }))
@@ -94,24 +68,24 @@ export default function Map({ state }) {
         style={{ width: '100%', maxWidth: W, display: 'block', margin: '0 auto' }}
         aria-label="Mediterranean trade map"
       >
-        {/* Sea — permanent darkness beyond fog of war */}
+        {/* Sea — permanent darkness */}
         <rect width={W} height={H} fill="#0d1a26" />
 
-        {/* Fog of war — land H7 cells, revealed by chapter */}
+        {/* Fog of war — land H7 cells at real geographic positions */}
         {WAYPOINT_IDS.map((id) => {
           const wp = WAYPOINTS[id]
           if (chapter < wp.chapter) return null
           const cells = cellData[id]
           if (!cells) return null
-          return cells.map((cell, cellIdx) => {
+          return cells.map((cell) => {
             if (!cell.is_land) return null
-            const pos = h7ApproxPos(id, cellIdx)
-            if (!pos) return null
+            // lat/lon now come directly from the API — real H7 centroids
+            const { x, y } = project(cell.lat, cell.lon)
             return (
               <circle
                 key={`${id}-${cell.h7}`}
-                cx={pos.x}
-                cy={pos.y}
+                cx={x}
+                cy={y}
                 r={H7_RADIUS}
                 fill="#2d3b2a"
                 stroke="#3a4a30"
@@ -126,7 +100,6 @@ export default function Map({ state }) {
         {ROUTE_ORDER.map((routeId) => {
           const route = ROUTES.find((r) => r.id === routeId)
           if (!route) return null
-          // Route visible when both endpoints are revealed
           const fromWp = WAYPOINTS[route.from]
           const toWp   = WAYPOINTS[route.to]
           if (chapter < fromWp.chapter || chapter < toWp.chapter) return null