Fix presolved

[Zebreu]

Note

Medium Risk
Changes how OR-Tools vehicle eligibility is enforced for nodes, which can affect feasibility and route assignments in presolved/warm-start runs. Risk is moderate because it touches core solver constraints but is localized to vehicle-allowlist handling.

Overview
Fixes vehicle eligibility constraints in the OR-Tools routing model by replacing SetAllowedVehiclesForIndex with direct VehicleVar(...).SetValues(...) restrictions.

This is applied to the deprecated clustering-based vehicle limiting, the presolved partition-to-vehicle pinning (and fallback for unpartitioned nodes), and the strict warm-start (reoptimize_subnodes == 'strict') path so nodes are consistently bound to the intended vehicle sets.

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