fix(map): read all relevant selection sources

frontend/src/hooks/useMapThemeSelectionInsights.test.ts

@@ -0,0 +1,40 @@
+import { describe, expect, it } from 'vitest'
+import { settleWithConcurrency } from './useMapThemeSelectionInsights'
+
+describe('settleWithConcurrency', () => {
+  it('keeps result order and never exceeds the acquisition limit', async () => {
+    let active = 0
+    let maximumActive = 0
+
+    const results = await settleWithConcurrency([0, 1, 2, 3, 4, 5], 3, async (value) => {
+      active += 1
+      maximumActive = Math.max(maximumActive, active)
+      await new Promise((resolve) => setTimeout(resolve, (5 - value) * 2))
+      active -= 1
+      return value * 10
+    })
+
+    expect(maximumActive).toBe(3)
+    expect(results).toEqual([
+      { status: 'fulfilled', value: 0 },
+      { status: 'fulfilled', value: 10 },
+      { status: 'fulfilled', value: 20 },
+      { status: 'fulfilled', value: 30 },
+      { status: 'fulfilled', value: 40 },
+      { status: 'fulfilled', value: 50 },
+    ])
+  })
+
+  it('retains individual acquisition failures without stopping the queue', async () => {
+    const results = await settleWithConcurrency(['ok', 'fail', 'later'], 2, async (value) => {
+      if (value === 'fail') {
+        throw new Error('provider unavailable')
+      }
+      return value.toUpperCase()
+    })
+
+    expect(results[0]).toEqual({ status: 'fulfilled', value: 'OK' })
+    expect(results[1].status).toBe('rejected')
+    expect(results[2]).toEqual({ status: 'fulfilled', value: 'LATER' })
+  })
+})