Remove Bifrost: replace test 4 with LiteLLM health check

- Remove BIFROST constant and fetch_bifrost_logs() from common.py
- Add LITELLM constant (localhost:4000)
- Replace test_memory.py test 4 (Bifrost pass-through) with LiteLLM health check

Fixes #5

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

tests/integration/common.py

@@ -11,7 +11,7 @@ import urllib.request
 
 # ── config ────────────────────────────────────────────────────────────────────
 DEEPAGENTS   = "http://localhost:8000"
-BIFROST      = "http://localhost:8080"
+LITELLM      = "http://localhost:4000"
 OPENMEMORY   = "http://localhost:8765"
 GRAMMY_HOST  = "localhost"
 GRAMMY_PORT  = 3001
@@ -156,19 +156,6 @@ def fetch_logs(since_s=600):
         return []
 
 
-def fetch_bifrost_logs(since_s=120):
-    """Return bifrost container log lines from the last since_s seconds."""
-    try:
-        r = subprocess.run(
-            ["docker", "compose", "-f", COMPOSE_FILE, "logs", "bifrost",
-             f"--since={int(since_s)}s", "--no-log-prefix"],
-            capture_output=True, text=True, timeout=10,
-        )
-        return r.stdout.splitlines()
-    except Exception:
-        return []
-
-
 def parse_run_block(lines, msg_prefix):
     """
     Scan log lines for the LAST '[agent] running: <msg_prefix>' block.