fix(ls): compact output (-72% tokens) + fix discover panic

- ls: rewrite to strip permissions/owner/group/dates, show only
  names with dir/ suffix and human sizes. Properly handle flag
  ordering (path -l), -lh, multi-paths, --all.
- discover: remove orphan diff pattern that caused index out of
  bounds panic (PATTERNS had 22 entries vs RULES 21)
- benchmark: add 8 ls test cases
- test-all: add 5 ls smoke tests

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>