v0.6.0

Added

• token_norm_status: a read-only tool that reports the session's tool calls,
  context usage, cost and effective tokens against the configured limits, plus
  the continue | warn | handoff | block recommendation enforcement would give
  right now. It reads the same accumulators as the reminders, so the two cannot
  disagree; unknown sessions report zeros, and the tool is absent when the
  budget plugin is not loaded.
• Benchmark harness (bench/run.mjs) with two fixture tasks, plus the pilot
  methodology and results write-up in docs/benchmark.md.