Stop each render from appending a dead tools path to the user PATH

Every Faust render, and every trial-loop lane, runs dotnet with a fresh
DOTNET_CLI_HOME under the temp directory. The SDK's first-run experience
appends "<home>\.dotnet\tools" to the persisted user PATH each time, and
DOTNET_SKIP_FIRST_TIME_EXPERIENCE does not stop that part. Seventy-nine
dead entries had accumulated (9,634 chars), past cmd's environment limit,
so anything spawned through cmd lost the tail of PATH — node included.

DOTNET_ADD_GLOBAL_TOOLS_TO_PATH=0 is the switch that governs the PATH
write. Set it everywhere a throwaway dotnet home is used; telemetry
opt-out rides along for the renderer since these homes never persist.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

src/AquaSynth.Faust/FaustCompiler.cs

@@ -323,6 +323,11 @@ public static class FaustCompiler
         {
             ["DOTNET_CLI_HOME"] = home,
             ["DOTNET_SKIP_FIRST_TIME_EXPERIENCE"] = "1",
+            // The first-run experience still appends "<home>\.dotnet\tools" to the
+            // persisted user PATH; with a fresh home per render that left one dead
+            // entry per render until the PATH blew past cmd's environment limit.
+            ["DOTNET_ADD_GLOBAL_TOOLS_TO_PATH"] = "0",
+            ["DOTNET_CLI_TELEMETRY_OPTOUT"] = "1",
             ["DOTNET_NOLOGO"] = "1",
             ["NUGET_PACKAGES"] = packages,
             ["APPDATA"] = appData,