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/.gitignore

@@ -1,13 +1,14 @@
 # Build output
 bin/
 obj/
+publish-out/
 
 # Visual Studio artifacts
 .vs/
 *.user
 *.suo
 
-# Test simulator Python venv (phase 01 onward)
+# Test simulator Python venv
 tests/sim/.venv/
 
 # mbproxy runtime logs (default location, see appsettings.json)