v0.10.0 — reliable memory

Reliable memory — five improvements that make ATS's memory more trustworthy and observable, each an extension of existing infrastructure rather than a rewrite.

• Degraded-retrieval transparency — find returns degraded + warnings + corpus.sourcesFailed when a corpus source or retrieval branch drops out, instead of silently serving a subset. The composite adapter records which child it dropped; a known-partial corpus is no longer cached as complete.
• Optional reranking — ats find --rerank adds a second-stage reranker over the RRF-fused pool (a built-in dependency-free lexical scorer, or pass your own cross-encoder/LLM function). Widens a rerankDepth pool then trims to limit; degrades to the fused order on failure.
• Usage observability — retrieval calls now log durationMs, and ats usage reports per-tool volume, empty/error/degraded rates, latency (avg + p95), re-query pairs, and top queries (--json for machine output, markdown otherwise).
• Duplicate / contradiction detection — ats dedup clusters near-duplicate tasks (dependency-free Jaccard over title + content + tags) and flags status/priority/due disagreements within a cluster as potential contradictions. Detection only; it never edits.
• Reactive token refresh — the TickTick adapter refreshes its OAuth token and retries once on a 401 (revoked / invalidated-early / wrong-expiry cases the proactive check misses), then surfaces an actionable "run ats auth login".

Lockstep release — all public @reneza/ats-* packages published at 0.10.0. Full history in CHANGELOG.md.