Both were pre-existing, unrelated to today's check-mix.py/gig-log.py work
(spotted while running the suite for that change).

test_orphan_orbits.py: 9 of 41 tests failed (16-row setlist vs a frozen "13",
and 6 HAND_MEASURED orbit sets vs the parser). Root cause confirmed by git log
+ grep, not a parser bug: the setlist grew from 13 to 16 tracks since the
fixture was written, and commit 2376e431 (2026-08-01, "d10 is the riser") added
a d10 safe-riser idiom to 5 of the hand-measured tracks (bombe_dj, wap,
you_my_sunshine, mafia_sans_serif, desire) after the 2026-07-28 hand
measurement date; piment_bresilien went the other way (d10->d9, PLN's own
request, commit 71bb9bc2/5e5a37ad). Fix: the setlist-length assertions are now
derived from an independent sed-based row count of the setlist file (same
pipeline check-tracks.sh uses) instead of a literal that rots every time PLN
adds a track; the HAND_MEASURED dict and the vague_de_crime->bombe_dj orphan
assertion are re-measured by hand (grep on each file's dN lines, not by
copying the parser's own output) against the corpus as it stands today. No
assertion loosened — 41/41 pass, same invariants, current facts.

test_lcxl3_display.py: pytest collected 0 items. Cause: this was written as a
plain script (module-level `check()` calls, run via `python3
tools/tests/test_lcxl3_display.py`), like test_setlist.py, with no `test_*`
function pytest could find — a file that cannot fail under pytest, i.e.
silent coverage loss. Converted to 30 ordinary pytest test_* functions (one
assert group per logical check), same assertions, nothing dropped or
loosened. Verified live: broke rec_line's hour rollover (divmod 3600->3601)
and watched test_rec_line_formats_hmmss_past_an_hour fail with the exact
wrong value (REC 1:02:02 vs 1:02:03), then reverted.

Suite: 234 passed/9 failed/2 skipped -> 273 passed/2 skipped (ignoring
test_setlist.py, a separate plain-script file, out of scope here — it already
breaks whole-directory pytest collection via a module-level sys.exit and
predates this fix). test_gig_log.py untouched: 169 passed before and after.