Connectivity to wire list

TASK: Connectivity to wire list.

A logical design defines nets. Each net lists the connector pins it joins (pin ids are "<connector>-<pin>").
Derive the physical wires that implement every net, using these rules:
1. A net with exactly 2 pins is one wire between those two pins.
2. A net with 3 or more pins uses one splice named "SP-<net name>", and one wire from each of its pins to that splice.
3. Gauge (AWG) is set by net name: names starting "PWR" are 18; starting "GND" are 16; all others are 22.
4. Exception to rule 3: every net listed in `shielded` uses 20, whatever its name.

Connectors:
[
  {"id":"C1","pins":9},
  {"id":"C2","pins":14},
  {"id":"C3","pins":6}
]

Nets:
[
  {"name":"PWR_001","pins":["C1-4","C3-3","C2-7","C2-3"]},
  {"name":"SIG_002","pins":["C2-4","C3-1","C1-6","C2-8","C1-3"]},
  {"name":"CAN_003","pins":["C2-1","C2-10","C2-13"]},
  {"name":"PWR_004","pins":["C3-4","C1-5","C2-11","C2-6","C3-2"]},
  {"name":"CAN_005","pins":["C2-9","C2-12","C1-9","C1-2","C3-6"]},
  {"name":"SIG_006","pins":["C1-1","C1-7"]}
]

shielded: []

Output format (JSON, exactly these keys):
```json
{
 "wires": [
  {
   "from": "C1-3",
   "to": "C4-7",
   "gauge": 22
  },
  {
   "from": "C2-1",
   "to": "SP-PWR_004",
   "gauge": 18
  }
 ]
}
```
List every wire. Order does not matter; direction of from/to does not matter.