One event per (session, page, channel) within an aligned window of
readTrail.dedupWindowMinutes (default 5): buckets are
floor(epoch / windowSeconds), and a unique (dedup_key, window_bucket)
pair collapses concurrent duplicates race-free at insert time — the
first access in a window is always recorded, a later duplicate lands on
the unique violation and is skipped quietly (a skipped duplicate is not
a gap; only real write failures still abort the read). Each row carries
windowSeconds, so the evidence states it represents a window, never a
request count.
Reconnects within a window stay one event; a new session records again
even for the same user; channels never collapse into each other; the
page-less attachment key uses the documented `-` placeholder. Load
evidence: 30 collab-token renewals inside one window produce exactly one
event (test), bounding a live editing session at ~12 events/hour/page.
Window semantics documented in ADR 0023, the VS-NfD security
documentation (#228) and as a hardening-guide line for the new setting
(care rule: same PR).
Refs #223.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AUtYMxwTCMHG9mVHnwbFg8
