Follow-ups on 9232031 per review:
- Module-level constants KD_PAUSE_BURST_MAX_S (0.2s),
KD_PAUSE_THINK_MAX_S (1.5s), KD_START_OF_ACTION_IDLE_S (2.0s).
Docstrings reference them by name; future calibration against real
session data only has to touch one place. Threshold for "started
a new action" raised from 1s → 2s — 1s catches too much
mid-command hesitation to be empirically bimodal.
- New column kd_max_pause_gap (seconds). The distracted bucket count
alone can't distinguish one 3s pause from three 60s pauses;
max-gap carries that signal in one cheap scalar (vs widening the
histogram to a fourth bucket).
- Scope-framing docstring above the whole kd_* section: intended
use is session clustering / tooling attribution, explicitly NOT
biometric identity, admission decisions, or ML-driven user ID.
Keeps a future well-intentioned contributor from walking the
project into legal/ethics territory by accident.
- TODO comment on kd_top_bigrams: v1's JSON-in-TEXT is fine for
"show the top digraphs on the attacker page". If bigram-similarity
queries become hot, promote to a session_bigram_stats(sid, bigram,
count, mean_iat_s) table or Postgres JSONB + GIN. Neither changes
the write-side ingester materially.
No new migration helper — pre-v1 schema additions go through
create_all on fresh DBs; the existing _migrate_session_profile_table
stays but does not get extended. Alembic lands at v1 and sweeps all
the ad-hoc migrations at once.
anti
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