chore: organize solution into module folders (Core/Server/Drivers/Client/Tooling)

Group all 69 projects into category subfolders under src/ and tests/ so the
Rider Solution Explorer mirrors the module structure. Folders: Core, Server,
Drivers (with a nested Driver CLIs subfolder), Client, Tooling.

- Move every project folder on disk with git mv (history preserved as renames).
- Recompute relative paths in 57 .csproj files: cross-category ProjectReferences,
  the lib/ HintPath+None refs in Driver.Historian.Wonderware, and the external
  mxaccessgw refs in Driver.Galaxy and its test project.
- Rebuild ZB.MOM.WW.OtOpcUa.slnx with nested solution folders.
- Re-prefix project paths in functional scripts (e2e, compliance, smoke SQL,
  integration, install).

Build green (0 errors); unit tests pass. Docs left for a separate pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests/MelsecAddressTests.cs

@@ -0,0 +1,116 @@
+using Shouldly;
+using Xunit;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests;
+
+[Trait("Category", "Unit")]
+public sealed class MelsecAddressTests
+{
+    // --- X / Y hex vs octal family trap ---
+
+    [Theory]
+    [InlineData("X0", (ushort)0)]
+    [InlineData("X9", (ushort)9)]
+    [InlineData("XA", (ushort)10)]      // hex
+    [InlineData("XF", (ushort)15)]
+    [InlineData("X10", (ushort)16)]     // hex 0x10 = decimal 16
+    [InlineData("X20", (ushort)32)]     // hex 0x20 = decimal 32 — the classic MELSEC-Q trap
+    [InlineData("X1FF", (ushort)511)]
+    [InlineData("x10", (ushort)16)]     // lowercase prefix
+    public void XInputToDiscrete_QLiQR_parses_hex(string x, ushort expected)
+        => MelsecAddress.XInputToDiscrete(x, MelsecFamily.Q_L_iQR).ShouldBe(expected);
+
+    [Theory]
+    [InlineData("X0", (ushort)0)]
+    [InlineData("X7", (ushort)7)]
+    [InlineData("X10", (ushort)8)]      // octal 10 = decimal 8
+    [InlineData("X20", (ushort)16)]     // octal 20 = decimal 16 — SAME string, DIFFERENT value on FX
+    [InlineData("X777", (ushort)511)]
+    public void XInputToDiscrete_FiQF_parses_octal(string x, ushort expected)
+        => MelsecAddress.XInputToDiscrete(x, MelsecFamily.F_iQF).ShouldBe(expected);
+
+    [Theory]
+    [InlineData("Y0", (ushort)0)]
+    [InlineData("Y1F", (ushort)31)]
+    public void YOutputToCoil_QLiQR_parses_hex(string y, ushort expected)
+        => MelsecAddress.YOutputToCoil(y, MelsecFamily.Q_L_iQR).ShouldBe(expected);
+
+    [Theory]
+    [InlineData("Y0", (ushort)0)]
+    [InlineData("Y17", (ushort)15)]
+    public void YOutputToCoil_FiQF_parses_octal(string y, ushort expected)
+        => MelsecAddress.YOutputToCoil(y, MelsecFamily.F_iQF).ShouldBe(expected);
+
+    [Fact]
+    public void Same_address_string_decodes_differently_between_families()
+    {
+        // This is the headline quirk: "X20" in GX Works means one thing on Q-series and
+        // another on FX-series. The driver's family selector is the only defence.
+        MelsecAddress.XInputToDiscrete("X20", MelsecFamily.Q_L_iQR).ShouldBe((ushort)32);
+        MelsecAddress.XInputToDiscrete("X20", MelsecFamily.F_iQF).ShouldBe((ushort)16);
+    }
+
+    [Theory]
+    [InlineData("X8")]     // 8 is non-octal
+    [InlineData("X12G")]   // G is non-hex
+    public void XInputToDiscrete_FiQF_rejects_non_octal(string bad)
+        => Should.Throw<ArgumentException>(() => MelsecAddress.XInputToDiscrete(bad, MelsecFamily.F_iQF));
+
+    [Theory]
+    [InlineData("X12G")]
+    public void XInputToDiscrete_QLiQR_rejects_non_hex(string bad)
+        => Should.Throw<ArgumentException>(() => MelsecAddress.XInputToDiscrete(bad, MelsecFamily.Q_L_iQR));
+
+    [Fact]
+    public void XInputToDiscrete_honors_bank_base_from_assignment_block()
+    {
+        // Real-world QJ71MT91 assignment blocks commonly place X at DI 8192+ when other
+        // ranges take the low Modbus addresses. Helper must add the base cleanly.
+        MelsecAddress.XInputToDiscrete("X10", MelsecFamily.Q_L_iQR, xBankBase: 8192).ShouldBe((ushort)(8192 + 16));
+    }
+
+    // --- M-relay (decimal, both families) ---
+
+    [Theory]
+    [InlineData("M0", (ushort)0)]
+    [InlineData("M10", (ushort)10)]     // M addresses are DECIMAL, not hex or octal
+    [InlineData("M511", (ushort)511)]
+    [InlineData("m99", (ushort)99)]     // lowercase
+    public void MRelayToCoil_parses_decimal(string m, ushort expected)
+        => MelsecAddress.MRelayToCoil(m).ShouldBe(expected);
+
+    [Fact]
+    public void MRelayToCoil_honors_bank_base()
+        => MelsecAddress.MRelayToCoil("M0", mBankBase: 512).ShouldBe((ushort)512);
+
+    [Fact]
+    public void MRelayToCoil_rejects_non_numeric()
+        => Should.Throw<ArgumentException>(() => MelsecAddress.MRelayToCoil("M1F"));
+
+    // --- D-register (decimal, both families) ---
+
+    [Theory]
+    [InlineData("D0", (ushort)0)]
+    [InlineData("D100", (ushort)100)]
+    [InlineData("d1023", (ushort)1023)]
+    public void DRegisterToHolding_parses_decimal(string d, ushort expected)
+        => MelsecAddress.DRegisterToHolding(d).ShouldBe(expected);
+
+    [Fact]
+    public void DRegisterToHolding_honors_bank_base()
+        => MelsecAddress.DRegisterToHolding("D10", dBankBase: 4096).ShouldBe((ushort)4106);
+
+    [Fact]
+    public void DRegisterToHolding_rejects_empty()
+        => Should.Throw<ArgumentException>(() => MelsecAddress.DRegisterToHolding("D"));
+
+    // --- overflow ---
+
+    [Fact]
+    public void XInputToDiscrete_overflow_throws()
+    {
+        // 0xFFFF + base 1 = 0x10000 — past ushort.
+        Should.Throw<OverflowException>(() =>
+            MelsecAddress.XInputToDiscrete("XFFFF", MelsecFamily.Q_L_iQR, xBankBase: 1));
+    }
+}