docs(scratch): handoff — триаж #5 закрыт, ревью APPROVED, идёт приёмка

- Зачем:
  - зафиксировать состояние конвейера #5 перед долгой живой приёмкой,
    чтобы новая сессия продолжила без потери контекста.
- Что:
  - в handoff добавлена дельта 23:10: обе находки FIXED (фрагменты ID
    с SHA-256-цепочкой), перепроверка линией B — APPROVED;
  - обновлено состояние стенда: им владеет сценарий приёмки;
  - в .scratch/issue5-run добавлены свежие отчёты, перепроверка и
    сценарий приёмки acceptance-issue5.sh.
- Проверка:
  - git show --stat; лог приёмки — до строки SCRIPT_EXIT_CODE=.

.scratch/issue5-run/review-focus-issue5-task.md

@@ -0,0 +1,43 @@
+# Review focus A: task conformance (issue #5)
+
+You are an independent reviewer, fresh session, no executor history. Do NOT
+modify sources, git state, or permanent environment. You may read anything
+and run focused tests.
+
+Repo: /home/dementev/sources/clickstream-ch-kafka-superset-demo, branch
+feature/mentee-path. Review scope: ALL uncommitted working-tree changes
+(git status/diff vs HEAD).
+
+Mandate the executor worked from:
+/tmp/claude-1000/-home-dementev-sources-clickstream-ch-kafka-superset-demo/0836e970-ee07-4f86-a61f-291f32da525a/scratchpad/mandate-issue5.md
+Also: docs/specs/2026-07-19-mentee-path-redesign.md («Решения» item 4,
+«Чего здесь не делаем»), .scratch/hitl-findings.md finding F9.
+
+Verify CONFORMANCE, not style:
+1. Full Kafka history reread is truly GONE from the next-day path (F9's
+   culprit removed, not bypassed conditionally).
+2. Seeding follows the mandated direction: import seeds from already-read
+   artifact topics; backfill seeds from the generated stream; no lazy
+   full-reread fallback anywhere; old local state fails with a clear
+   Russian error telling to re-run import.
+3. Boundaries: generation not parallelized (single PRNG stream untouched);
+   no incremental ETL; retention untouched; reference artifact file in git
+   unchanged (git diff must not touch data/); docs/course/ untouched.
+4. Issue #5 acceptance criteria coverage: cumulative counters (sums,
+   uid/click_id sets, rolling checksum) in state/manifest; day N ~ day 1
+   plausible from the code path (O(new day events)); required equality test
+   exists and genuinely compares incremental vs full recompute; `check`
+   operation semantics preserved.
+5. Docs updated where state/manifest semantics are user-visible.
+
+Findings: stable IDs TASK-N; each with severity, file:line, violated
+criterion, failure scenario + evidence, minimal way to verify.
+Non-blocking considerations: no ID, no severity.
+VERDICT: APPROVED only if no finding requires a code/docs change; bare
+APPROVED without listing reviewed scope and performed checks does not count.
+
+Write the full report (English) to:
+/tmp/claude-1000/-home-dementev-sources-clickstream-ch-kafka-superset-demo/0836e970-ee07-4f86-a61f-291f32da525a/scratchpad/review-issue5-task.md
+
+Final message: VERDICT, severity counters, one line per finding, one line
+per significant non-blocking consideration, report path.