adapter instantiation system? user might want slightly customized manifests/manifest overrides. examples:
- normal CC
- `ccs` for work account
- a fancy one with extra Stop hook wiring i.e. for invoker agents to respond promptly, or for the session to clean itself up a la `claude -p`

## MORE ADAPTABLE ALT: ADAPTER PROFILES
- adapter profiles are identical to the adapter manifest, but don't need to be explicitly registered
- instead, each **adapter profile manifest** is listed as a named profile inside the main adapter manifest
- from there, both the main adapter manifest and its child profile manifests are all treated as different adapter options by spt-core

### tangential feature: adapter strings
enable adapters and adapter profiles to store unique information under JSON KV stores.

from there, the endpoint binary (i.e. harness) itself can fetch i.e. an 'additionalContext' string using something like `spt adapter get-string <adapter profile name> <key.subkey>`. would need to confirm that this even works in + is valuable for harness features like claude code hooks.