Add unit tests for analytics, fallback client, and refactored validators

- Implemented comprehensive unit tests for the BuddAI Analytics module, covering fallback statistics calculations.
- Created tests for the FallbackClient to ensure proper escalation to various AI models and handling of missing API keys.
- Developed unit tests for the refactored validator system, validating various hardware and coding standards.
- Established a base validator interface and implemented specific validators for ESP32, Arduino, motor control, memory safety, and more.
- Enhanced the validator registry to auto-discover and manage validators effectively.
- Included detailed validation logic for common issues in embedded systems programming, such as unused variables, safety timeouts, and coding style violations.

core/buddai_memory.py

@@ -349,6 +349,20 @@ class SmartLearner:
         conn.commit()
         conn.close()
 
+    def store_rule(self, pattern: str, confidence: float, source: str):
+        """Store a single rule from fallback or other sources"""
+        conn = sqlite3.connect(DB_PATH)
+        cursor = conn.cursor()
+        
+        cursor.execute("""
+            INSERT INTO code_rules 
+            (rule_text, pattern_find, pattern_replace, confidence, learned_from)
+            VALUES (?, ?, ?, ?, ?)
+        """, (pattern, "", "", confidence, source))
+        
+        conn.commit()
+        conn.close()
+
     def diff_code(self, original: str, corrected: str) -> str:
         """Generate a simple diff"""
         return "\n".join(difflib.unified_diff(