Fixed context bleeding and revised system prompt.

app.py

@@ -53,7 +53,7 @@ def generate_flowchart(src_code: str) -> str:
     1. OUTPUT FORMAT: Output ONLY valid, raw Mermaid.js syntax.
     2. NO MARKDOWN FENCING: Do not wrap the output in ```mermaid or ``` blocks. Start directly with the Mermaid graph definition, for example: graph TD.
     3. NO PROSE: Do not include introductory text, explanations, or concluding remarks. If the code cannot be parsed, output an isolated error node.
-    4. NODE NAMING: Keep text inside the flowchart nodes descriptive but concise, under 5 words.
+    4. NODE NAMING: Paraphrase conditions into plain words — never put raw code, operators, quotes, or parentheses inside labels (write Index in bounds?, not i < len(nums))
     </constraints>
 
     <banned_vocabulary>
@@ -94,6 +94,9 @@ def generate_flowchart(src_code: str) -> str:
         B -- False --> D[Return 'Inactive']
     """).strip()
 
+    # Reset the cache per request so no cross-request bleeding
+    llm.reset()
+
     # Casting else PyLance gets mad
     response = cast(Any, llm.create_chat_completion(
         messages=[
@@ -109,9 +112,12 @@ def generate_flowchart(src_code: str) -> str:
 
     # remove the thinking tags from the response
     cleaned = re.sub(r'<thinking>.*?</thinking>', '', content, flags=re.DOTALL)
-    # Mermaid can't parse double quotes inside [node labels] (e.g. C[Return "Active"]);
-    # source-code string literals leak them, so downgrade to single quotes which parse fine.
+
+    # Remove raw quotes on both parentheses and non-parentheses
     cleaned = cleaned.replace('"', "'")
+    cleaned = re.sub(r'\[([^\[\]]+)\]', r'["\g<1>"]', cleaned)
+    cleaned = re.sub(r'\{([^{}]+)\}', r'{"\g<1>"}', cleaned)
+    
     return cleaned.strip() # and remove excess whitespace
 
 # ----- Custom Frontend ----- #