Animation output fails: directory creation disabled blocks MP4 generation

[krystophny]

DEFECT: Animation functionality broken due to security compliance directory creation disabled

REPRODUCTION:

1. Run save_animation_demo executable
2. Animation creation fails with 'No such file or directory'
3. Error: 'Output directory creation disabled for security compliance'

EVIDENCE:

• FFmpeg available and working
• PNG frames generated successfully
• MP4 output fails: output/example/fortran/animation/animation.mp4 directory missing
• Error log: 'Info: Output directory creation disabled for security compliance'

USER IMPACT: HIGH - Animation feature completely broken for users
ROOT CAUSE: Security compliance broke core functionality
RESPONSIBLE: Sprint #2 security changes broke user workflows

SOLUTION: Enable controlled directory creation for animation output paths