perf(server): cap SQLite WAL size after checkpoints

The WAL file grows to its largest-ever size and never shrinks. Set
journal_size_limit so SQLite truncates it back to 16 MiB whenever a
checkpoint resets the log.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y1jWssjvT14xf2uw1daK7Z
3efa5ef2eaClaude committed on 9/25/2026, 11:33:58 PMparented809f7
2 files changedLine totals unavailable