Replace colon-delimited device strings in wire metadata with device-name-only references

[kabanaty]

Problem

Wire device metadata (in wire_metadata.yaml) stores associated devices as colon-delimited strings encoding two pieces of information — the device name and its area:

WS01:
  detectors:
    - PMTINJ03:DL1
    - PMTINJ05:DL1
    - PMT21350:LI21
  default_detector: PMTINJ03:DL1

Every consumer of this metadata must manually split these strings to extract the device name and area:

slac_measurements/wires/collection.py:153-154

for ds in self.beam_profile_device.metadata.detectors:
    name, area = ds.split(":")
    detector = _instantiate_device(name, area)

slacwire/widgets/measurement.py:85-86

for detector_string in detectors:
    detector, area = detector_string.split(":")

This pattern is repeated across at least 6 locations in slac-measurements and slacwire. It is error-prone, not self-documenting, and couples the metadata format to string parsing logic throughout the codebase.

Proposed Solution

Replace colon-delimited strings with bare device names and use Beampath.find_device() for resolution.

After the recent Beampath refactor, find_device(device_name) searches all areas and returns the area, device type, and device object making the area encoding in metadata redundant:

result = beampath.find_device("PMTINJ03")
# Returns: ("DL1", "pmts", <PMT object>)

The metadata would simplify to:

WS01:
  detectors:
    - PMTINJ03
    - PMTINJ05
    - PMT21350
  default_detector: PMTINJ03

Consumer code becomes:

detectors = [
    beampath.find_device(name)
    for name in self.beam_profile_device.metadata.detectors
]

Benefits

• Eliminates repeated string-splitting logic across the codebase
• Single source of truth for device-to-area mapping (the Beampath object)
• Metadata becomes simpler and less brittle
• Device lookup is type-safe and returns a full device object rather than raw strings

Affected Files

• slac-db/slac_db/package_data/wire_metadata.yaml — metadata source
• slac-devices/slac_devices/wire.py — WireMetadata model (type annotations change from List[str] to device-name-only semantics)
• slac-measurements/slac_measurements/wires/collection.py — primary consumer with multiple split sites
• slacwire/slacwire/widgets/measurement.py — GUI consumer
• slacwire/slacwire/ws_gui.py — GUI consumer