Presentability: neutralize competition-meta, tidy logbook pages

retag: pages

retag: drop stale pages/

Update logbook: PlugMem — Task-Agnostic Plugin Memory Module

Claim 4 scaled LongMemEval runtime evidence (0/3, qwen3:4b)

Fix: replace erroneous CacheAttack content with correct PlugMem logbook

Update logbook: Repro: ICML 2026 Agent Security Papers