feat: add --cprofile flag for runtime profiling

Writes cProfile stats to a file on shutdown for performance analysis.
Enable in compose.yaml for container profiling.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

compose.yaml

@@ -15,4 +15,4 @@ services:
     volumes:
       - ./src:/app/src:Z,ro
       - ./config:/data:Z
-    command: ["-c", "/data/bouncer.toml", "-v"]
+    command: ["-c", "/data/bouncer.toml", "-v", "--cprofile", "/data/bouncer.prof"]