DRAKHYSYS INFINITY TILESET WORKBENCH V4.1 BMP + PVRZ AUTO

Fix:
- Reads the actual PVRZ page indices directly from the selected TIS V1 tile table.
- Automatically searches for every required PVRZ beside the TIS.
- You no longer need to choose page 00 and page 01 manually one by one.
- If one page is selected manually, it is used as a filename-prefix/location hint and the remaining required pages are added automatically.
- Missing-page errors now show the exact filenames required.

Example:
DR0001.TIS references pages 00 and 01. If D000100.PVRZ and D000101.PVRZ are beside DR0001.TIS, LOAD + RECONSTRUCT TILESET will load both automatically.

HT/LM/SR BMP export from V4 is preserved.
