v3.1.0 — zero-hot routing and multi-agent accounting

v3.1.0 — zero-hot routing and multi-agent accounting

This release removes the measurable idle tax that v3.0.1 exposed.

What changed

• Codex and Claude keep the saver skill outside their visible skill catalogs.
• Automatic fuzzy routing is strict, emits nothing when uncertain and activates at most one primary skill.
• A conservative built-in gate still handles explicit token/context tasks when the companion router is absent.
• minimal is truly zero-hot: CLI and ledger only, with no visible skill or prompt hook.
• agent-token-ledger now sums named parent/child usage files and fingerprints duplicate visible context.

Neutral evidence

Clean CODEX_HOME ABBA microbenchmark:

• Baseline median: 11,204 input.
• Lean median: 11,209 input.
• Delta: +5 input tokens / +0.045%.
• Cache and output identical; every answer passed.

This is a no-tool idle-cost result, not an end-to-end savings multiplier. The
146.1x number remains a separate accepted payload-capacity benchmark.

Accepted explicit-RTK Codex probe:

• raw ps aux: 25,210 input
• explicit rtk ps aux: 23,996 input
• 1,214 fewer full input tokens (4.82%), identical 19,968 cached subset

One failed no-command warmup remains recorded and excluded from the accepted
A/B. Transparent Codex RTK rewriting is still not claimed.