* feat(byok): migrate agent/router/evaluator LLM keys to BYOK by model prefix
* fix(script): address review — cover translate/guardrails, trim provider ids, reject mixed mapping, add key-prefix guard
* fix(script): include pi block in LLM-family set, trim key-prefix value
* fix(script): add router_v2 to LLM-family set, canonicalize provider ids to lowercase
* fix(script): resolve overlapping model prefixes deterministically (longest match wins)