fix(romhacks): build on Alpine DCE base (apk + self-contained CLI)

The tyrrrz/discordchatexporter image is Alpine, not Debian, and ships DCE as a
self-contained executable (no dotnet on PATH). Use apk for python3 and invoke
/opt/app/DiscordChatExporter.Cli directly.

stacks/romhacks/orchestrator/orchestrate.py

@@ -57,22 +57,23 @@ def slug(s):
 
 
 def find_dce():
-    direct = "/opt/app/DiscordChatExporter.Cli.dll"
+    # Self-contained single-file executable in the Alpine DCE image (no `dotnet`).
+    direct = "/opt/app/DiscordChatExporter.Cli"
     if os.path.exists(direct):
         return direct
-    hits = glob.glob("/opt/**/DiscordChatExporter.Cli.dll", recursive=True)
+    hits = glob.glob("/opt/**/DiscordChatExporter.Cli", recursive=True)
     return hits[0] if hits else None
 
 
 def run_dce(channel_id):
-    dll = find_dce()
-    if not dll:
-        print("[romhacks] DiscordChatExporter.Cli.dll not found in image", file=sys.stderr)
+    dce = find_dce()
+    if not dce:
+        print("[romhacks] DiscordChatExporter.Cli not found in image", file=sys.stderr)
         return False
     out = EXPORTS / channel_id
     out.mkdir(parents=True, exist_ok=True)
     cmd = [
-        "dotnet", dll, "export",
+        dce, "export",
         "-t", TOKEN,
         "-c", channel_id,
         "-f", "Json",