Harden customize-item mod parsing to reject malformed entries and prevent persistent bad equips

[Copilot]

Malformed customize_item_* payloads could be loaded even when required fields were missing, allowing invalid items to be equipped and persisted in save data. This change tightens parser acceptance criteria so malformed customization entries are dropped before they can be emitted back into mods.

• Problem scope

  • customize_item_common_list.bin and customize_item_unique_list.bin accepted structurally invalid rows (e.g., missing IDs or asset keys), which could propagate bad customization records.

• Parser hardening

  • Added entry-level validators for customization records:
    • common entries require non-zero item_id and non-empty key text fields.
    • unique/body entries require non-zero item ID + non-empty asset_name.
  • ParseCustomizeItemCommonJson now appends only validated entries.
  • ParseCustomizeItemUniqueListJson now returns failure when both arrays are empty after validation.

• Generic array parsing behavior

  • Updated ParseExclusiveArray(...) to only push entries when parseFn(...) returns true, enabling per-entry rejection consistently across call sites.

• Load-path gating

  • LoadFromPath(...) now conditionally adds customize_item_unique_list.bin only when parsing succeeds, aligning with existing guarded behavior used for other bins.

• User recovery guidance

  • Added a concise README recovery section for already-corrupted saves: re-enable offending mod, unequip to vanilla, resave, then remove mod; fallback to pre-corruption backup/clean profile if persistence remains.

static bool IsValidCustomizeItemUniqueEntry(const CustomizeItemUniqueEntry& e)
{
    return e.char_item_id != 0 && IsNonEmptyText(e.asset_name);
}

template<typename TEntry, typename TParseFunc>
static void ParseExclusiveArray(const char* json, const char* arrayKey,
                                std::vector<TEntry>& out, TParseFunc parseFn)
{
    ...
    TEntry entry{};
    if (parseFn(arr, objEnd, entry))
        out.push_back(entry);
}