fix(web): duplicate result warnings in results table

setAnalysisResults is called for each incoming result with all
accumulated results. Since seqNameDuplicatesAtom was never cleared,
the same index was appended repeatedly, causing false duplicate
warnings in the UI.

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

Author: ivan-aksamentov

packages/nextclade-web/src/state/results.state.ts

@@ -1,6 +1,6 @@
 /* eslint-disable no-void */
 import type { AuspiceJsonV2, CladeNodeAttrDesc } from 'auspice'
-import { isNil } from 'lodash'
+import { isNil, union } from 'lodash'
 import { atom, selectorFamily } from 'recoil'
 import { atom as jotaiAtom } from 'jotai'
 import { atomFamily as jotaiAtomFamily } from 'jotai/utils'
@@ -65,7 +65,7 @@ export const analysisResultAtom = jotaiAtomFamily((index: number) =>
 
       // Add to the duplicate names map
       const currentDuplicates = get(seqNameDuplicatesAtom(result.seqName))
-      set(seqNameDuplicatesAtom(result.seqName), [...currentDuplicates, result.index])
+      set(seqNameDuplicatesAtom(result.seqName), union(currentDuplicates, [result.index]))
     },
   ),
 )