refactor(driver-s7): extract S7DriverOptions to .Contracts with parallel CpuType enum

Introduces Driver.S7.Contracts (dependency-free POCO project) and moves
S7DriverOptions / S7ProbeOptions / S7TagDefinition / S7DataType into it.
Adds S7CpuType enum mirroring S7.Net.CpuType exactly (7 values with
explicit integer codes). Runtime S7CpuTypeMap bridges S7CpuType →
S7.Net.CpuType at the single Plc construction site in S7Driver.InitializeAsync.
S7DriverFactoryExtensions and S7CommandBase updated to use S7CpuType; test
files updated to match (S7_1500Profile, S7DriverScaffoldTests). AdminUI can
now reference Driver.S7.Contracts without pulling in S7netplus.

src/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.S7.Cli/S7CommandBase.cs

@@ -1,6 +1,5 @@
 using CliFx.Attributes;
 using ZB.MOM.WW.OtOpcUa.Driver.Cli.Common;
-using S7NetCpuType = global::S7.Net.CpuType;
 
 namespace ZB.MOM.WW.OtOpcUa.Driver.S7.Cli;
 
@@ -24,7 +23,7 @@ public abstract class S7CommandBase : DriverCommandBase
     [CommandOption("cpu", 'c', Description =
         "S7 CPU family: S7200 / S7200Smart / S7300 / S7400 / S71200 / S71500 " +
         "(default S71500). Determines the ISO-TSAP slot byte.")]
-    public S7NetCpuType CpuType { get; init; } = S7NetCpuType.S71500;
+    public S7CpuType CpuType { get; init; } = S7CpuType.S71500;
 
     /// <summary>Gets the rack number.</summary>
     [CommandOption("rack", Description = "Rack number (default 0 — single-rack).")]