Fixed bug in mermaid output

app.py

@@ -37,7 +37,7 @@ def generate_flowchart(src_code: str) -> str:
     # check if src_code is empty
     if not src_code.strip(): return ""
 
-    # Set system prompt.
+    # Set system prompt
     system_prompt = dedent("""
     ## Role/Persona
     You are a senior staff software architect and compiler engineer specializing in visual control-flow mapping. Your philosophy is pure utility: you translate raw execution logic into highly accurate, scannable, structural diagrams without any conversational filler, meta-commentary, or stylistic fluff.
@@ -104,20 +104,11 @@ def generate_flowchart(src_code: str) -> str:
 
     content = response["choices"][0]["message"]["content"]
 
-    # ----- DEBUG ----- #
-    print("=" * 40)
-    print("FINISH REASON:", response["choices"][0].get("finish_reason"))
-    print("RAW CONTENT >>>")
-    print(repr(content))          # repr so we see whitespace / empty
-    print("<<< END RAW")
-
-    cleaned = re.sub(r'<thinking>.*?</thinking>', '', content, flags=re.DOTALL)
-    print("CLEANED >>>", repr(cleaned.strip()))
-    print("=" * 40)
-    # ----- END DEBUG ----- #
-
     # remove the thinking tags from the response
-    # cleaned = re.sub(r'<thinking>.*?</thinking>', '', content, flags=re.DOTALL)
+    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.
+    cleaned = cleaned.replace('"', "'")
     return cleaned.strip() # and remove excess whitespace
 
 # ----- Custom Frontend ----- #