refactor: Beute-Frontend vereinfacht (findPart, subVec3, seededRandom)

Gemeinsame Helfer statt vier Kopien der Teilsuche, zwei Vektor-
Subtraktionen und zwei Zufallsgeneratoren; hasPartSheet an einer
Stelle; ungenutzte setOpacity und points-Ref entfernt. Verhalten
unverändert (1050 Tests).

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

ApiCore-Frontend/src/components/hive/hive-focus-bar.tsx

@@ -2,7 +2,8 @@
 
 import { useEffect } from "react";
 import { ArrowLeft, SlidersHorizontal } from "lucide-react";
-import type { HiveCatalog, HivePart, HiveState } from "@/lib/hive/types";
+import { findPart } from "@/lib/hive/find-part";
+import type { HiveCatalog, HiveState } from "@/lib/hive/types";
 import { GLASS_PILL, GLASS_SURFACE } from "./hive-glass";
 import { formatAmount } from "./hive-scene/scene-model";
 
@@ -15,15 +16,6 @@ export interface FocusChip {
   text: string;
 }
 
-function findPart(state: HiveState, id: string): HivePart | undefined {
-  for (const part of state.stack) {
-    if (part.id === id) return part;
-    const insert = part.inserts?.find((candidate) => candidate.id === id);
-    if (insert) return insert;
-  }
-  return undefined;
-}
-
 /** Chips for the focused part: frame count of a box, every state field with its value. */
 export function focusChips(state: HiveState, catalog: HiveCatalog, id: string): FocusChip[] {
   const part = findPart(state, id);