**feat: refactor agent loop to state machine with dynamic trajectory checks**

- Replace hard-coded `MAX_REPL_STEPS` death-limit with a dynamic Checkpoint Interval.
- Introduce 4-phase state machine: `PLANNING`, `EXECUTING`, `TRAJECTORY_CHECK`, and `PIVOTING`.
- Add Trajectory Checks allowing the agent to self-assess progress against defined success criteria to extend its execution budget.
- Implement Hard (wipe strategy/kernel) and Soft (retry step) Pivoting logic.
- Establish persistent notebook-style kernel (flushed only on Hard Pivots).
- Upgrade sandbox safety with strict import whitelisting, dunder blocking, and taint tracking.

**bugfix:

- logging_config.py: Add markdown_it to suppressed logger list
- utils.py: Rewrite save_agent_trace for delta-based logging
- edge_rlm.py: Add last_trace_msg_count tracking and pass deltas at all 3 call sites

utils.py

@@ -10,6 +10,13 @@ from rich.panel import Panel
 logger = logging.getLogger(__name__)
 console = Console()
 
+WHITELISTED_IMPORTS = {
+    "json", "math", "datetime", "re", "collections",
+    "statistics", "random", "difflib", "string",
+}
+
+DANGEROUS_BUILTINS = {"eval", "exec", "compile"}
+
 
 def init_trace_file(log_dir="logs"):
     if not os.path.exists(log_dir):
@@ -20,12 +27,15 @@ def init_trace_file(log_dir="logs"):
     logger.debug("Trace logging initialized: %s", filename)
     return filename
 
-def save_agent_trace(filepath, messages, step=0):
+def save_agent_trace(filepath, new_messages, step=0, state=None, plan_step=0, total_messages=0):
     try:
         data_to_save = {
             "timestamp": time.time(),
             "step": step,
-            "context_window": messages
+            "state": state,
+            "plan_step": plan_step,
+            "total_messages": total_messages,
+            "new_messages": new_messages,
         }
 
         with open(filepath, 'a', encoding='utf-8') as f:
@@ -35,6 +45,15 @@ def save_agent_trace(filepath, messages, step=0):
         logger.error("Failed to save trace file: %s", e)
 
 
+def _check_dunder_access(node):
+    if isinstance(node, ast.Attribute) and node.attr.startswith("__") and node.attr.endswith("__"):
+        return True
+    if isinstance(node, ast.Subscript):
+        if isinstance(node.slice, ast.Constant) and isinstance(node.slice.value, str):
+            if node.slice.value.startswith("__") and node.slice.value.endswith("__"):
+                return True
+    return False
+
 def _analyze_code_safety(code_str):
     try:
         tree = ast.parse(code_str)
@@ -45,6 +64,23 @@ def _analyze_code_safety(code_str):
     has_print = False
 
     for node in ast.walk(tree):
+        if isinstance(node, ast.Import):
+            for alias in node.names:
+                if alias.name not in WHITELISTED_IMPORTS:
+                    return False, f"Import Violation: '{alias.name}' is not whitelisted. Allowed: {', '.join(sorted(WHITELISTED_IMPORTS))}.", node.lineno
+
+        if isinstance(node, ast.ImportFrom):
+            if node.module not in WHITELISTED_IMPORTS:
+                return False, f"Import Violation: '{node.module}' is not whitelisted. Allowed: {', '.join(sorted(WHITELISTED_IMPORTS))}.", node.lineno
+
+        if _check_dunder_access(node):
+            name = None
+            if isinstance(node, ast.Attribute):
+                name = node.attr
+            elif isinstance(node, ast.Subscript):
+                name = getattr(node.slice, 'value', getattr(node.slice, 's', None))
+            return False, f"Dunder Access Violation: Accessing '{name}' is forbidden.", getattr(node, 'lineno', None)
+
         if isinstance(node, ast.Assign):
             if isinstance(node.value, ast.Name) and node.value.id in tainted_vars:
                 for target in node.targets:
@@ -52,6 +88,10 @@ def _analyze_code_safety(code_str):
                         tainted_vars.add(target.id)
 
         if isinstance(node, ast.Call):
+            if isinstance(node.func, ast.Name):
+                if node.func.id in DANGEROUS_BUILTINS:
+                    return False, f"Builtin Violation: '{node.func.id}()' is forbidden.", node.lineno
+
             if isinstance(node.func, ast.Name) and node.func.id == 'print':
                 has_print = True
                 for arg in node.args:
@@ -230,6 +270,48 @@ Write the final response in natural language (Markdown).
         {"role": "user", "content": user_prompt}
     ])
 
+def validate_plan_object(obj):
+    if not isinstance(obj, dict):
+        return False, "PlanObject must be a JSON object."
+    for key in ("goal", "strategy", "success_criteria"):
+        if key not in obj:
+            return False, f"PlanObject missing required key '{key}'."
+    if not isinstance(obj["goal"], str) or not obj["goal"].strip():
+        return False, "PlanObject 'goal' must be a non-empty string."
+    if not isinstance(obj["strategy"], list) or len(obj["strategy"]) == 0:
+        return False, "PlanObject 'strategy' must be a non-empty list of strings."
+    if not isinstance(obj["success_criteria"], list) or len(obj["success_criteria"]) == 0:
+        return False, "PlanObject 'success_criteria' must be a non-empty list of strings."
+    if len(obj["strategy"]) != len(obj["success_criteria"]):
+        return False, "PlanObject 'strategy' and 'success_criteria' must have the same length."
+    for i, s in enumerate(obj["strategy"]):
+        if not isinstance(s, str) or not s.strip():
+            return False, f"PlanObject 'strategy[{i}]' must be a non-empty string."
+    for i, s in enumerate(obj["success_criteria"]):
+        if not isinstance(s, str) or not s.strip():
+            return False, f"PlanObject 'success_criteria[{i}]' must be a non-empty string."
+    return True, None
+
+
+def validate_pivot_object(obj):
+    if not isinstance(obj, dict):
+        return False, "PivotObject must be a JSON object."
+    if "diagnosis" not in obj:
+        return False, "PivotObject missing required key 'diagnosis'."
+    if not isinstance(obj["diagnosis"], str) or not obj["diagnosis"].strip():
+        return False, "PivotObject 'diagnosis' must be a non-empty string."
+    if "new_strategy" in obj or "new_success_criteria" in obj:
+        if "new_strategy" not in obj or "new_success_criteria" not in obj:
+            return False, "PivotObject: 'new_strategy' and 'new_success_criteria' must both be present or both omitted."
+        if not isinstance(obj["new_strategy"], list) or len(obj["new_strategy"]) == 0:
+            return False, "PivotObject 'new_strategy' must be a non-empty list of strings."
+        if not isinstance(obj["new_success_criteria"], list) or len(obj["new_success_criteria"]) == 0:
+            return False, "PivotObject 'new_success_criteria' must be a non-empty list of strings."
+        if len(obj["new_strategy"]) != len(obj["new_success_criteria"]):
+            return False, "PivotObject 'new_strategy' and 'new_success_criteria' must have the same length."
+    return True, None
+
+
 def load_file(filepath):
     try:
         with open(filepath, 'r', encoding='utf-8') as f: