Fix KeyError when baseline database is missing

Added 'summary' key to error return paths in analyze() method.
This fixes the crash when running performance tests for the first time
without a baseline database.

Tested locally: script now exits gracefully with exit code 0 when
no baseline is available.

Co-Authored-By: Alex Peng <[email protected]>

Author: devin-ai-integration[bot]

scripts/performance-regression-detector.py

@@ -170,7 +170,13 @@ def analyze(self) -> Dict[str, Any]:
                 "message": "No baseline results available for comparison",
                 "regressions": [],
                 "improvements": [],
-                "stable": []
+                "stable": [],
+                "summary": {
+                    "total_benchmarks": 0,
+                    "regressions_found": 0,
+                    "improvements_found": 0,
+                    "stable_benchmarks": 0
+                }
             }
 
         if not current_results:
@@ -180,7 +186,13 @@ def analyze(self) -> Dict[str, Any]:
                 "message": "No current results found",
                 "regressions": [],
                 "improvements": [],
-                "stable": []
+                "stable": [],
+                "summary": {
+                    "total_benchmarks": len(baseline_results),
+                    "regressions_found": 0,
+                    "improvements_found": 0,
+                    "stable_benchmarks": 0
+                }
             }
 
         for baseline in baseline_results: