api/machines: allow importing extra modules

- add top-level option `clanImports` to clanCore
- clanImports can be set and checked as any other option
- buildClan resolves the clanImports from the settings.json before calling evalModules to prevent infinite recursions
- new endpoint PUT machines/{name}/schema to allow getting the schema for a specific list of imports
- to retrieve the currently imported modules, cimply do a GET or PU on machines/{name}/config which will return `clanImports` as part of the config

Still missing: get list of available modules

pkgs/clan-cli/clan_cli/webui/routers/machines.py

@@ -69,6 +69,14 @@ async def get_machine_schema(name: str) -> SchemaResponse:
     return SchemaResponse(schema=schema)
 
 
+@router.put("/api/machines/{name}/schema")
+async def set_machine_schema(
+    name: str, config: Annotated[dict, Body()]
+) -> SchemaResponse:
+    schema = schema_for_machine(name, config)
+    return SchemaResponse(schema=schema)
+
+
 @router.get("/api/machines/{name}/verify")
 async def put_verify_machine_config(name: str) -> VerifyMachineResponse:
     error = verify_machine_config(name)