v2.7.0 — Kiro CLI backend

Adds a new LLM backend option: kiro-cli. The daemon can now invoke the Kiro CLI instead of calling Bedrock or OpenAI directly, which is useful when you're running Kiro locally and want the daemon to reuse its agent session.

Changes:

• Add kiro-cli as a supported llm_backend value
• Pass --agent flag to the Kiro CLI invocation to reduce token overhead on repeated calls
• Update project title in README

Config:

[llm_backend]
name = "kiro-cli"

No region or credentials required — the backend shells out to the Kiro CLI binary already installed on the host.