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/triage-issue5.md

@@ -0,0 +1,53 @@
+# Triage round: issue #5 — both review lines, coordinator header
+
+You are the executor continuing your own issue #5 implementation (working
+tree on branch feature/mentee-path; your original mandate:
+mandate-issue5.md in this same directory, your report: report-issue5.md).
+Do the per-finding triage and fix.
+
+## Coordinator header (agreements / contradictions / boundary notes)
+
+- Both independent lines converge on ONE blocking defect:
+  CODE-1 (line B, code quality) == TASK-1 (line A, task conformance).
+  The cumulative manifest payload carries exact click_id/uid sets:
+  ~0.81 MB already on the reference world, Kafka default 1 MiB message
+  limit is not overridden anywhere → manifest save fails after roughly one
+  more next-day. Size is O(history); the issue's disease moves from
+  read-time to a write-time ceiling. No contradictions between the lines.
+- Line B additionally: CODE-2 (Low) — next-day saves state before manifest
+  (import does the reverse), widening the half-advanced window.
+- Full reports (read them directly):
+  - line B (code): review-issue5-code.md (same directory)
+  - line A (task): review-issue5-task.md (verdict text; sandbox blocked its
+    full file write)
+
+## Coordinator decisions for the fix (boundaries, not design)
+
+- The issue's GOAL is time O(new day), no full Kafka reread, no OOM risk.
+  Linear GROWTH of stored counter state over days is acceptable on a demo
+  stand — a hard silent ceiling is not. Whatever representation you choose,
+  the failure mode must be explicit and far away, and the write path must
+  not break within the demo's realistic horizon (say, world age of
+  hundreds of days).
+- Manifest numbers must stay EXACT (the check against ClickHouse uniqExact
+  is the learning value) — no approximate sketches.
+- Reference artifact in git stays unchanged; determinism invariants from
+  the original mandate stay in force.
+- Prefer the simplest solution that meets the above (учебная ценность:
+  a mentee should be able to read and understand it). If two viable
+  options differ in product trade-offs (e.g. raising Kafka topic limits vs
+  restructuring the payload), pick one, implement it, and justify; return
+  NEEDS_DECISION only if the choice genuinely changes user-visible
+  behaviour or issue acceptance criteria.
+
+## What to return
+
+For each finding ID (CODE-1/TASK-1 as one item is fine, CODE-2): one status
+line `ID | FIXED/REJECTED/OUT_OF_SCOPE/NEEDS_DECISION | essence + evidence`.
+Details go to the report: APPEND a "## Triage round 1" section to
+report-issue5.md (same directory): chosen representation and why, measured
+payload size on the reference world after the fix, projection of growth,
+new/changed tests, make test / make lint exit codes.
+
+Rules unchanged: no commits, no changes to data/ artifact, docs updated in
+the same change if state/manifest semantics shift.