## What changed
- Compact executor and orchestrator skill locators under metadata pressure, using provider-specific `e` and `o` aliases alongside host `r` aliases.
- Derive alias roots from executor discovery paths and orchestrator namespaces while preserving host plugin root handling.
- Centralize alias ordering, deduplication, and longest-prefix matching across skill providers.
## Testing
- Cover alias planning, cross-platform executor roots, and host plugin discovery.
GitOrigin-RevId: e7d15bd3891c08ae20170e96c4ad45c76d353707