Migrate to FMOD 2.03.09 with test harnesses

[utgarda]

Summary

Migrates libfmod from FMOD 2.02.22 to 2.03.09 and adds comprehensive test harnesses for validating the migration and demonstrating FMOD Studio features.

Changes

Migration (09dc708)

• Updated to FMOD Engine 2.03.09
• Fixed breaking API changes (System::getVersion, FMOD_ADVANCEDSETTINGS)
• Added compatibility layer for new SDK structure

Test Infrastructure (e5b1983, 3f4acc6, 33e31d2)

• harness_demo - Automated demos of 3D spatial audio, event parameters, footsteps
• interactive_harness - Interactive keyboard-controlled 3D audio testing
• run_fmod.sh - Helper script for running examples with correct library paths

Testing

All examples tested on Linux x86_64 with FMOD 2.03.09. Run with:

cd libfmod
./run_fmod.sh harness_demo
./run_fmod.sh interactive_harness

Breaking Changes

- Requires FMOD SDK 2.03.09
- Not ABI compatible with FMOD 2.02.x