retention piece 1: immediate rotations for chat-history / job-log / followups (b67084660385)

- chat-history.jsonl rotates at 10MB or 7d -> logs/archive/*.jsonl.gz + .sha256
- job-log.jsonl rotates at 2MB or 14d -> same archive layout
- followups.json archives resolved>7d / escalated>30d -> followups.archive.jsonl (append-only)
- verify wrapper: sha256 -c, gzip -t, clean listing, spot-extract JSON + ts bounds
- driver + hourly systemd user timer (retention-rotations.timer)
- archive-only: nothing is ever deleted; thread backfill excluded (needs human-reviewed preview)
First run 2026-10-05 16:35Z: chat-history 29.7MB + job-log 4.7MB rotated and verified; followups 0 eligible of 163.

systemd/retention-rotations.service

@@ -0,0 +1,10 @@
+[Unit]
+Description=NetVM retention rotations (piece 1: chat-history / job-log / followups)
+After=network.target
+
+[Service]
+Type=oneshot
+ExecStart=/home/super/Projects/NetVM/bin/retention-run-rotations.sh
+WorkingDirectory=/home/super/Projects/NetVM
+StandardOutput=journal
+StandardError=journal