fix: remove circleguardbench git dependency to fix build

The circleguardbench git dependency was causing build failures.
Removed it from requirements.txt and made imports lazy in submit.py.
The leaderboard display works without the package; only submission
processing requires it.

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

requirements.txt

@@ -6,4 +6,4 @@ apscheduler>=3.10.0
 python-dotenv>=1.0.0
 plotly>=5.18.0
 pydantic==2.10.6
-circleguardbench @ git+https://github.com/whitecircle-ai/circle-guard-bench.git@b1e0d82
+scikit-learn>=1.0.0

src/submission/submit.py

@@ -18,9 +18,14 @@ import subprocess
 from src.display.formatting import styled_error, styled_message
 from src.envs import RESULTS_DATASET_ID, TOKEN, REPO_ID
 from src.leaderboard.processor import process_jsonl_submission
-from circleguardbench.evaluator import Evaluator
-from circleguardbench.context import GuardbenchContext
-from circleguardbench.models_config import ModelType
+
+try:
+    from circleguardbench.evaluator import Evaluator
+    from circleguardbench.context import GuardbenchContext
+    from circleguardbench.models_config import ModelType
+    GUARDBENCH_AVAILABLE = True
+except ImportError:
+    GUARDBENCH_AVAILABLE = False
 
 
 def validate_submission(file_path: str) -> Tuple[bool, str]:
@@ -124,6 +129,9 @@ def process_submission(file_path: str, metadata: Dict, version="v0") -> str:
     """
     Process a submission to the GuardBench leaderboard.
     """
+    if not GUARDBENCH_AVAILABLE:
+        return styled_error("circleguardbench package is not installed. Submission processing is unavailable.")
+
     try:
         # Validate submission
         is_valid, validation_message = validate_submission(file_path)