Depends on #53.

7 new Enum types for valve/actuator classification:

• ValveFunction — piping role (11 values: isolation, control, balancing, bypass, check, mixing, diverting, pressureReducing, expansion, safety, relief). Scoped to single-select piping role — pressureIndependent and thermostatic are feature markers per Add Valve and Damper abstract base specs #53.
• ValveBodyType — physical construction (ball, butterfly, gate, globe, needle, plug)
• ValvePorts — port configuration (twoWay, threeWay, fourWay)
• ActuatorFailPosition — fail-safe mode (failOpen, failClosed, failInPlace, failToPosition)
• ActuatorDirection — signal mapping (directActing, reverseActing)
• ActuatorControlAction — control behavior (modulating, twoPosition, floating)
• ActuatorMechanism — drive type (electricMotor, pneumatic, hydraulic, solenoid)

actuatorDirection added as a slot on Actuator — it's the one classification that's an active input to control logic and belongs directly on the spec.

Files: ph/enums.xeto, ph/equip.xeto