Follow-up suggested during PR #275's merge review: spec-pinning tests for
the language_gate/language_note fields, matching the pattern already used
for the sibling gaps/strengths fields in this same file.
Four new assertions: Step 2's scoring-agent JSON schema declares both
fields with the PASS/FAIL/FLAG enum and distinguishes them from the
pre-existing `language` field; Step 3 documents the Language veto rule
mirroring the existing Location veto; Step 4 persists both fields into
seen_jobs.json; Step 5's presentation rules document the FLAG marker.
The Step 4 persistence test is a real regression guard, not just
documentation: language_gate/language_note were computed in Step 2 and
used to decide Step 3's veto, but an earlier version of this spec never
instructed Step 4 to actually write them to seen_jobs.json - caught via
live debugging (a real /rank run showed language_gate: null on every
entry despite the run reporting genuine vetoes), fixed once already.
Verified live that this test fails against that exact regression and
passes against the current (fixed) spec text.
/rank's Step 2 scoring agents already return strengths and gaps per job,
but Step 4 only persisted rank_score/rank_verdict/rank_date - both arrays
were printed once in Step 5 and then discarded. Store them verbatim in
seen_jobs.json (replaced, not accumulated, on --all re-ranks) so downstream
consumers can read real triage findings instead of re-deriving them.
Discussed in #258.