I made nearly the same idea but centered around semantic search with a pluggable embedding service and sqlite caching https://github.com/Sornaensis/adrai so it's just a CLI tool you tell your agents to use.

ADRs are organized by a domain hierarchy and can relate directly to individual files and path globs.

I find this absolutely improves cohesive development because it lets analysis and review agents scope ADRs with `adrai relevant path/to/file.rs` and `adrai search "blah blah"` And the ADR coverage can be more comprehensive and well organized without leading to too much context bloat if the models have to rediscover things all the time.