[peterswimm]

Description

TinyXML writes the project through Tiny2NosStub's fprintf, which formatted every piece into a 256 byte stack buffer with vsprintf. An attribute longer than that, such as a sample with a very long file name, ran past it, overwriting the stack and leaving lgptsav.dat cut short mid-write.

Now it formats with vsnprintf, and prints anything longer into a heap buffer of the right size.

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Built from master with this change and run on the device below.

Test Configuration:

• Hardware: Anbernic RG35XX SP
• Test steps: save a project holding an attribute longer than 256 characters (e.g. a sample with a ~250 character file name). Before the fix the save crashes or leaves the file cut short; after it, the project saves and loads back.

Checklist:

• I have performed a self-review of my code
• I have commented particularly in hard-to-understand areas
• I have updated CHANGELOG (left for the maintainer to place under the next build)
• I have updated docs/wiki/What-is-LittlePiggyTracker.md reflecting my changes (no user-facing change to document)
• I have version bumped in sources/Application/Model/Project.h (will bump if asked)
• My changes generate no new warnings (removes the vsprintf warning in Tiny2NosStub.cpp; checked on macOS)

An LLM (Claude) was used to help find the bug and write the patch; I read the diff and tested it myself.