Handle Nincada split evolution (Ninjask + Shedinja)

When evolving Nincada, a confirmation prompt now offers to also add
Shedinja as a new encounter on the same route. The Shedinja encounter
uses a "shed_evolution" origin to bypass route-locking.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/pages/RunDashboard.tsx

@@ -2,7 +2,7 @@ import { useState } from 'react'
 import { useParams, Link } from 'react-router-dom'
 import { useRun, useUpdateRun } from '../hooks/useRuns'
 import { useGameRoutes } from '../hooks/useGames'
-import { useUpdateEncounter } from '../hooks/useEncounters'
+import { useCreateEncounter, useUpdateEncounter } from '../hooks/useEncounters'
 import { StatCard, PokemonCard, RuleBadges, StatusChangeModal, EndRunModal } from '../components'
 import type { RunStatus, EncounterDetail } from '../types'
 
@@ -26,6 +26,7 @@ export function RunDashboard() {
   const runIdNum = Number(runId)
   const { data: run, isLoading, error } = useRun(runIdNum)
   const { data: routes } = useGameRoutes(run?.gameId ?? null)
+  const createEncounter = useCreateEncounter(runIdNum)
   const updateEncounter = useUpdateEncounter(runIdNum)
   const updateRun = useUpdateRun(runIdNum)
   const [selectedEncounter, setSelectedEncounter] =
@@ -243,6 +244,9 @@ export function RunDashboard() {
           onClose={() => setSelectedEncounter(null)}
           isPending={updateEncounter.isPending}
           region={run?.game.region}
+          onCreateEncounter={(data) => {
+            createEncounter.mutate(data)
+          }}
         />
       )}
 

frontend/src/pages/RunEncounters.tsx

@@ -1269,6 +1269,9 @@ export function RunEncounters() {
           onClose={() => setSelectedTeamEncounter(null)}
           isPending={updateEncounter.isPending}
           region={run?.game.region}
+          onCreateEncounter={(data) => {
+            createEncounter.mutate(data)
+          }}
         />
       )}