feat: add Pencil+ 4 host configuration scripts for 3ds Max 2025 and 2027

[ZainAallii]

Adds two HC scripts that install Pencil+ 4 (PSOFT) alongside 3ds Max 2025/2027 on Windows Service-Managed Fleets.

Pencil+ renders watermark-free under 3dsmaxcmd.exe (NTR mode) without license server configuration. The scripts follow the same pattern as the existing V-Ray/Corona/tyFlow samples.

What is included

• 3dsmax-2025-and-pencilplus-4.ps1
• 3dsmax-2027-and-pencilplus-4.ps1 (includes ADP known-issue callout)
• README sample-index rows for both

Script features beyond the base template

• Inno Setup silent-install flags documented (with the /S-is-NSIS-not-Inno warning)
• Post-install verification (hard-fails HC if Pencil+ plugin files are missing)
• S3 download error handling (fails immediately with a clear message instead of cascading)
• Installer filename derived from the S3 URI variable (stays in sync)

Testing

Tested on a Windows SMF with 3ds Max 2025 + Pencil+ 4.2.7. Renders completed watermark-free via 3dsmaxcmd.exe.

[crowecawcaw]

Looks like this need a rebase

[github-actions]

This change prepends a UTF-8 BOM (U+FEFF) to the start of README.md. The only diff on this line is the invisible BOM before #, so the file previously had no BOM. A leading BOM in a Markdown file is unintended noise: some tooling (and some Markdown renderers) treat the BOM as part of the heading text, and it can break tooling that expects the file to start with a literal #. Recommend re-saving README.md as UTF-8 without BOM so this line is byte-identical to before. (A BOM on the new .ps1 files is fine and even helpful for PowerShell encoding detection — this note is only about the Markdown file.)

[github-actions]

The new 3dsmax-2027-and-pencilplus-4.ps1 renders in server mode via 3dsmaxcmd.exe/3dsmaxbatch.exe, so it is subject to the documented "Autodesk ADP Failed to start" issue just like the other 2027 scripts. Its script header correctly links to that section, but the ADP section itself (line 76) enumerates the affected scripts — 3dsmax-2027, 3dsmax-2027-and-vray, 3dsmax-2027-and-corona-14, 3dsmax-2027-and-vray-and-tyflow, 3dsmax-2027-vray-and-aec-plugins — and this new script is missing from that list. Consider adding 3dsmax-2027-and-pencilplus-4 there so the "applies to" enumeration stays complete.