v0.17.0

What's Changed

• feat(prompt): add --prompt-file and take the prompt off argv when large by David Koleczek (@DavidKoleczek) in #152
• fix(http): prompt_tokens double-counted cache reads on the OpenAI wire by Salil Das (@sadlilas) in #154
• feat(spawn): bridge delegated sub-agent cost to the parent session by Salil Das (@sadlilas) in #155
• docs(hook_streaming): correct why _sum_cost_usd is not foundation's sum_cost_usd by Salil Das (@sadlilas) in #156
• feat(engine): report real per-turn token usage in the envelope and wrapper events by David Koleczek (@DavidKoleczek) in #153
• docs: lead the integration story with the engine library by David Koleczek (@DavidKoleczek) in #157
• chore(release): cut amplifier-agent 0.17.0 by David Koleczek (@DavidKoleczek) in #158

Full Changelog: v0.16.0...v0.17.0