- Cargo.toml: remove `thiserror` from kb-config, kb-parse-types, kb-app
(unused — none of those crates' src trees reference thiserror; CoreError
in kb-core is the only consumer).
- kb-config keeps the `kb-core` dep with a one-line comment marking
CoreError reserved for P1-* config-error wiring per the review thread.
- ids.rs: switch `validate_hex32` from a hand-rolled `matches!` byte range
to `is_ascii_hexdigit()` so the hex check is the canonical idiom (and
satisfies `clippy::manual_is_ascii_check` under `-D warnings`).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>