feat(repair): inject ebike + pylon parts at packderelance anchors

- Ebike replacement parts: cooling core (correct, anchored at refroidisseur)
  + four distractors anchored at cabledroit/cablegauche/pucehaut/pucebas.
  Removes the ad-hoc gant_l/talkie distractors in favor of consistent
  case-anchored visuals.
- Pylon replacement parts: cable1 + cable2 (alternative correct, both with
  caseLockGroup 'pylon-cable' for upcoming soft-lock) + refroidisseur and
  two puce distractors anchored to packderelance.
- Farm replacement parts kept as-is (caseAnchor undefined falls back to
  placeholder slot positions for backward compatibility).
- RepairGame threads anchors from RepairCaseModel through RepairMissionCase
  to RepairRepairingStep; replacement-part initial position now resolves
  to the anchor world position when caseAnchor is set, falling back to the
  legacy slot index otherwise.

src/components/three/gameplay/RepairMissionCase.tsx

@@ -1,5 +1,6 @@
 import {
   RepairCaseModel,
+  type RepairCasePartAnchors,
   type RepairCasePlaceholder,
 } from "@/components/three/gameplay/RepairCaseModel";
 import { RepairPromptVideo } from "@/components/three/gameplay/RepairPromptVideo";
@@ -19,6 +20,7 @@ interface RepairMissionCaseProps {
   onPlaceholdersChange?:
     | ((placeholders: readonly RepairCasePlaceholder[]) => void)
     | undefined;
+  onAnchorsChange?: ((anchors: RepairCasePartAnchors) => void) | undefined;
   onExitComplete?: (() => void) | undefined;
   open?: boolean;
   zoomed?: boolean;
@@ -30,6 +32,7 @@ export function RepairMissionCase({
   config,
   exiting = false,
   onPlaceholdersChange,
+  onAnchorsChange,
   onExitComplete,
   open = false,
   zoomed = false,
@@ -57,6 +60,7 @@ export function RepairMissionCase({
             exiting={exiting}
             onExitComplete={onExitComplete}
             onPlaceholdersChange={onPlaceholdersChange}
+            onAnchorsChange={onAnchorsChange}
             open={open}
             floating={!zoomed}
             position={modelPosition}
@@ -70,6 +74,7 @@ export function RepairMissionCase({
           exiting={exiting}
           onExitComplete={onExitComplete}
           onPlaceholdersChange={onPlaceholdersChange}
+          onAnchorsChange={onAnchorsChange}
           open={open}
           floating={!zoomed}
           position={modelPosition}