#508 Chore: delete 10 dead diagnostic/scratch files

[Anonymous]

Originally created by: Redo-San

All 10 are git-tracked, all 10 appear in knip's Unused files (134) list, and a repo-wide search for every basename returns zero references. tests/ is excluded from the repo scanners anyway.

• tests/diag_markers_tmp.js
• tests/diag_nocov_tmp.js
• tests/diag_repro_tmp.js
• tests/diag_trace_tmp.js
• tests/diag_voice_e2e_tmp.js
• tests/fix_dump2.js
• tests/fix_ensure.js
• tests/fix_test3.js
• cli/tests/e2e/e2e_pixel_diag.js
• cli/tests/e2e/e2e_pixel_diag2.js

Acceptance criteria

• [ ] rg for each basename → 0 hits.
• [ ] npm run knip unused-file count drops from 134 to 124.
• [ ] npm run check:quick passes.