docs: backfill XML documentation across 756 files

Adds <summary>, <param>, <typeparam>, and <inheritdoc/> tags to public
members surfaced by commentchecker — resolves 5,847 of 5,869 issues
(99.6%) across three /fixdocs passes.

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/Mitsubishi/MitsubishiProfile.cs

@@ -23,6 +23,9 @@ public static class MitsubishiProfile
     /// <summary>Value the smoke test writes then reads back.</summary>
     public const short SmokeHoldingValue = 7890;
 
+    /// <summary>Builds Modbus driver options configured for the Mitsubishi profile.</summary>
+    /// <param name="host">The Modbus server hostname or IP address.</param>
+    /// <param name="port">The Modbus server port number.</param>
     public static ModbusDriverOptions BuildOptions(string host, int port) => new()
     {
         Host = host,

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/Mitsubishi/MitsubishiQuirkTests.cs

@@ -19,6 +19,7 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests.Mitsubishi;
 [Trait("Device", "Mitsubishi")]
 public sealed class MitsubishiQuirkTests(ModbusSimulatorFixture sim)
 {
+    /// <summary>Verifies that Mitsubishi D0 register fingerprint reads the expected value 0x1234.</summary>
     [Fact]
     public async Task Mitsubishi_D0_fingerprint_reads_0x1234()
     {
@@ -34,6 +35,7 @@ public sealed class MitsubishiQuirkTests(ModbusSimulatorFixture sim)
         r[0].Value.ShouldBe((ushort)0x1234);
     }
 
+    /// <summary>Verifies that Mitsubishi Float32 with CDAB word order decodes correctly to 1.5 from D100.</summary>
     [Fact]
     public async Task Mitsubishi_Float32_CDAB_decodes_1_5f_from_D100()
     {
@@ -59,6 +61,7 @@ public sealed class MitsubishiQuirkTests(ModbusSimulatorFixture sim)
         r[1].Value.ShouldNotBe(1.5f, "same wire with BigEndian must decode to a different value");
     }
 
+    /// <summary>Verifies that Mitsubishi D registers store binary values, not BCD.</summary>
     [Fact]
     public async Task Mitsubishi_D10_is_binary_not_BCD()
     {
@@ -77,6 +80,7 @@ public sealed class MitsubishiQuirkTests(ModbusSimulatorFixture sim)
         r[0].Value.ShouldBe((short)1234, "MELSEC stores numeric D-register values in binary; 0x04D2 = 1234");
     }
 
+    /// <summary>Verifies that reading a binary D register as BCD throws when the value contains non-decimal nibbles.</summary>
     [Fact]
     public async Task Mitsubishi_D10_as_BCD_throws_because_nibble_is_non_decimal()
     {
@@ -97,6 +101,7 @@ public sealed class MitsubishiQuirkTests(ModbusSimulatorFixture sim)
         r[0].StatusCode.ShouldNotBe(0u, "BCD decode of binary 0x04D2 must fail loudly because nibble D is non-BCD");
     }
 
+    /// <summary>Verifies that Mitsubishi Q/L/iQ-R X inputs use hex addressing and X210 maps correctly.</summary>
     [Fact]
     public async Task Mitsubishi_QLiQR_X210_hex_maps_to_DI_528_reads_ON()
     {
@@ -117,6 +122,7 @@ public sealed class MitsubishiQuirkTests(ModbusSimulatorFixture sim)
         r[0].Value.ShouldBe(true);
     }
 
+    /// <summary>Verifies that X input address mapping differs between Mitsubishi MELSEC families (Q vs FX).</summary>
     [Fact]
     public void Mitsubishi_family_trap_X20_differs_on_Q_vs_FX()
     {
@@ -127,6 +133,7 @@ public sealed class MitsubishiQuirkTests(ModbusSimulatorFixture sim)
         MelsecAddress.XInputToDiscrete("X20", MelsecFamily.F_iQF).ShouldBe((ushort)16);
     }
 
+    /// <summary>Verifies that Mitsubishi M512 relay maps to coil address 512 and reads ON.</summary>
     [Fact]
     public async Task Mitsubishi_M512_maps_to_coil_512_reads_ON()
     {

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/Mitsubishi/MitsubishiSmokeTests.cs

@@ -15,6 +15,7 @@ namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests.Mitsubishi;
 [Trait("Device", "Mitsubishi")]
 public sealed class MitsubishiSmokeTests(ModbusSimulatorFixture sim)
 {
+    /// <summary>Verifies end-to-end write and read of a Mitsubishi holding register via the Modbus driver.</summary>
     [Fact]
     public async Task Mitsubishi_roundtrip_write_then_read_of_holding_register()
     {