The Upload-Verlauf tab took 30s+ to open on large, never-cleared histories.
Measured on the live config: 18.9 MB config / 41 batches / 53,403 rendered rows.
Two independent problems, fixed together:
1. Render side (the 30s killer): renderHistoryTable built ALL rows into one
innerHTML. Now the build is capped to the newest 2,000 rows (HISTORY_RENDER_CAP)
after slicing the chronological tail, then sorted for display. A notice shows
"Zeige neueste 2000 von N" so nothing looks deleted; full history stays on disk
and "Verlauf exportieren" still emits everything (export reads loadHistory()).
2. Storage side: history grew unbounded because appendHistory only ever pushed.
New globalSettings.historyRetention ('all' default, non-destructive) with
policies: 7d / 30d / 90d (time-based) and 1000 / 100 (newest-uploads-based).
appendHistory now prunes after each batch; a new prune-history IPC re-applies
the policy immediately when the user changes it, gated behind a confirm() that
shows the exact removal count (dry-run first).
Prune model keeps whole batches (atomic): count policies accumulate rendered rows
from the newest batch backward and always keep >= the newest batch even if it
alone exceeds the target; time policies keep batches whose timestamp is missing
or unparseable (old entries have none) so ambiguous data is never silently dropped.
New retention dropdown lives in the Verlauf header. 9 unit tests cover the prune
edge cases incl. a realistic 41-batch fixture. Full suite: 272 pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
05ad08433c