Remove 5 DELETE-category generator files identified in bf-1iefu:
- tests/fixtures/scanned/generate_scanned_fixtures.rs (Rust stub, use Python version)
- tests/fixtures/security/generate_sensitive_fixture.py (duplicate, Rust version preferred)
- tests/fixtures/encoding/generate_unmapped_glyphs.rs (superseded by Python version)
- tests/fixtures/malformed/gen-bomb-10k-2g.sh (superseded by Python version)
- tests/fixtures/forms/generate_form_fixtures.d (orphaned Makefile dependency)
Verification: No compiled object files (.o, .so, .a, .dylib, .dll) or executable binaries found. The .bin files in fixtures root are test data files, not compiled artifacts.