feat(process): process metrics by track — segments, returns, ship findings, job minutes (#728)

The weekly report could not say whether the tracks of #695/#696 paid off:
it read only the first S4/S5/S7/S8 placements of closed issues, no track,
no waiting, no reason for a return, and the CLI never passed jobs, so the
"Job-минуты" line never printed. The owner decides on these numbers, so the
definitions are spelled out in the report headers and anything unknown is
printed as such.

scripts/process-metrics.mjs (pure functions over the snapshot):
- K1 trackAt/trackPath: track at a moment from the labels set before it,
  resolved by process-track.mjs (labelTrack) — one rule with the pipeline;
  infra = no class A file in the issue's commits (Release: commits aside).
  The issue's track is the one at its first S8-merged.
- K2 issueSegments: queue/spec/work/review/rework/blocked from the first
  status label to the first S8, summing to lead; blocked is taken out of
  the segment under it; S7 over S7 is neither a return nor a new segment.
- K3 returnSignal/returnReason: S7 -> S6/S3 and S4 -> S3 returns, reason
  from the last comment with a sign between the review placement and the
  return. merge and the "not run" family come from PIPELINE_EVENTS, the
  verdicts from verdictDeclaration with the issue's own document; the two
  continuations have no pipeline constant, so NOT_RUN_VALIDATE_RE and
  NOT_RUN_CONFLICT_RE are exported copies held by a contract test on the
  _process.yml templates. Anything else is unknown; hp:route (#726)
  gives reclassify/owner-question when present.
- K4 shipFindings: High/Medium/Low of SHIP-REVIEW-*.md (docs/reviews and
  legacy/reviews) by the anchor block, summed per issue; the track table
  counts each document once.
- K5 stageMinutes: jobs of process and Validate runs (skipped runs aside,
  at most 600, "усечено: N из M" beyond), stages by job name, per track at
  run time, Validate per event; unavailable jobs are "нет данных", not 0.
  jobMinutes gets the same data and prints again.
- K6 tokenUsage: "Токены: нет данных (…)" until the pipeline records usage
  (issue F); the hp:usage line format is provisional.
- K7 compareCohorts: issues with the first S8 within 28 days before and
  after 2026-09-28 (--compare, --compare-days), cohort = track x volume
  bucket (<=30/31-200/201-1000/>1000 lines of Issue-trailer commits without
  Release:, class D and docs/reviews/**); n < 3 on a side is "мало данных".
- fetchSnapshot: issues state=all since the earliest window (the old
  selection is still "closed in the window"), timelines up to 10 pages
  (beyond: "таймлайн усечён"), jobs, ship and usage review docs, git log
  --numstat of origin/dev.

_process-metrics.yml: full history (fetch-depth: 0) for K1/K7 and a 30
minute ceiling. The thin process-metrics.yml is unchanged. PROCESS.md §5
points at the report. Old sections and their tests are unchanged.

Issue: #728
User-Visible: no
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018qZfe7YS4rqEMKoVeS3GKd

.github/workflows/_process-metrics.yml

@@ -5,6 +5,12 @@ name: "Метрики процесса · тело (#623)"
 # идёт в step summary и артефакт; в issue и репозиторий ничего не пишется.
 # Цифры аудита 22.09 (1,57 раунда код-ревью, S7 ≈ 36 мин/раунд, 226 Validate
 # за неделю) были собраны руками за час — теперь они стоят один запуск.
+#
+# #728: эффект процесса по трекам — отрезки, возвраты с причинами, находки
+# ship, job-минуты по стадиям и сравнение до/после 28.09. Прогон дороже:
+# jobs до 600 прогонов и таймлайны задач окна сравнения (≈ 600–800 запросов),
+# поэтому потолок 30 минут; трек инфраструктуры и объём задачи читаются из
+# истории git — нужна полная история dev.
 
 on:
   # #623: тело вызывается тонким файлом `process-metrics.yml` из ветки по умолчанию
@@ -26,14 +32,15 @@ jobs:
   metrics:
     name: "Снимок недели: issue, раунды, прогоны"
     runs-on: ubuntu-24.04
-    timeout-minutes: 15
+    timeout-minutes: 30
     steps:
       # Код — из dev, как у reconcile: расписание читается из main, а исполняется
-      # версия, которую проверил CI.
+      # версия, которую проверил CI. Полная история (#728): коммиты задачи по
+      # трейлеру `Issue: #NN` дают признак инфраструктуры и объём для сравнения.
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
         with:
           ref: dev
-          fetch-depth: 1
+          fetch-depth: 0
           persist-credentials: false
       - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7
         with: