## Why
Environment attachments can either inherit configuration from their thread or
provide their own. Later thread setting updates must refresh inherited
configuration without overwriting attachment-owned permissions and capability
roots.
## What changed
- Resolve each attachment's configuration when it is selected and retain
whether it came from the thread or the attachment owner.
- Apply subsequent thread configuration updates only to thread-owned
attachments, while preserving ownership across snapshots and child threads.
- Keep the resolved configuration with the environment selection so runtime
consumers use a single canonical value.
## Testing
- Extend remote-environment coverage to verify that thread-owned permissions
follow thread updates while owner-provided read-only permissions remain in
effect.
- Cover configuration inheritance, attachment replacement, and owner-configured
capability roots.
GitOrigin-RevId: fe70c4be5f151432b69bf4b141e316faa89036ae
sayan-oai
22bf16a37e