mbproxy: strip historical phase/wave/plan references from source comments

Comments described the *history* of how the code arrived (phase numbers,
wave IDs, review IDs, dated TODOs) instead of what it does today. That
scaffolding rotted as the codebase evolved. Cleaned 60 source files +
.gitignore; behaviour unchanged (387/387 tests still pass).

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

mbproxy/tests/Mbproxy.Tests/Proxy/ProxyForwardingTests.cs

@@ -51,13 +51,12 @@ public sealed class ProxyForwardingTests
     }
 
     // ── 2a. FC03 read HR1072 — with BCD configured → decoded 1234 ──────────────────────
-    // Replaced Phase 03 placeholder: Forward_FC03_HR1072_Returns_RawBCD_0x1234
 
     [Fact(Timeout = 5_000)]
     public async Task Forward_FC03_HR1072_Returns_Decoded_1234()
     {
-        // Phase 04: BcdPduPipeline is active. When BCD tag 1072 (width=16) is configured,
-        // the proxy decodes the raw 0x1234 nibbles and the client receives binary 1234.
+        // BcdPduPipeline is active. When BCD tag 1072 (width=16) is configured, the proxy
+        // decodes the raw 0x1234 nibbles and the client receives binary 1234.
         if (_sim.SkipReason is not null)
             Assert.Skip(_sim.SkipReason);
 
@@ -230,9 +229,9 @@ public sealed class ProxyForwardingTests
     public async Task BackendConnectFailure_ClosesUpstreamCleanly()
     {
         // Point the proxy at port 1 on loopback — guaranteed unreachable.
-        // After Phase 9 the multiplexer lazily connects to the backend on the first
-        // upstream PDU, so we have to actually send a request before the proxy attempts
-        // the (failing) backend connect that closes the upstream.
+        // The multiplexer lazily connects to the backend on the first upstream PDU, so
+        // we have to actually send a request before the proxy attempts the (failing)
+        // backend connect that closes the upstream.
         const int badBackendPort = 1;
         const int backendTimeoutMs = 500; // short timeout for test speed
 
@@ -352,7 +351,7 @@ public sealed class ProxyForwardingTests
             new Serilog.LoggerConfiguration().MinimumLevel.Fatal().CreateLogger(),
             dispose: false);
         builder.AddMbproxyOptions();
-        // BCD rewriter pipeline — used by the Phase 04 tests in this file.
+        // BCD rewriter pipeline — used by the BCD-decode tests in this file.
         builder.Services.AddSingleton<IPduPipeline, BcdPduPipeline>();
         builder.Services.AddHostedService<ProxyWorker>();
         return builder.Build();