PMM-15326: Regenerate the tasks OpenAPI spec and client for /hosts/states/

Derived, not authored: `tests/app/test_openapi_specs_fresh.py` runs
`scripts/dump_openapi.py --check` and fails the moment a route exists that the
committed spec does not carry, so the regeneration has to ride in the same change
that adds the route. Kept as its own commit so the previous one is only the code a
reviewer has to read.

Both files are what the tooling produces, not what a hand wrote:
`specs/tasks.json` from `scripts/dump_openapi.py` and `src/generated/tasks.ts` from
`pnpm --filter @sep/api codegen` followed by `oxfmt --write src/generated`, which is
`make regen-specs` minus the snapshot goldens no route here touches.

103 lines added to the spec and 101 to the client, none removed: the path, the
`ExecutorHostState` schema, and the operation type. The other two clients and the
other two specs are untouched, which is the check that this branch carries only its
own share of the contract.

Author: plebioda