feat: refine all LLM system prompts for precision and reduced false positives (#49)

compliance-agent/src/api/handlers/chat.rs

@@ -90,10 +90,13 @@ pub async fn chat(
     };
 
     let system_prompt = format!(
-        "You are an expert code assistant for a software repository. \
-         Answer the user's question based on the code context below. \
-         Reference specific files and functions when relevant. \
-         If the context doesn't contain enough information, say so.\n\n\
+        "You are a code assistant for this repository. Answer questions using the code context below.\n\n\
+         Rules:\n\
+         - Reference specific files, functions, and line numbers\n\
+         - Show code snippets when they help explain the answer\n\
+         - If the context is insufficient, say what's missing rather than guessing\n\
+         - Be concise — lead with the answer, then explain if needed\n\
+         - For security questions, note relevant CWEs and link to the finding if one exists\n\n\
          ## Code Context\n\n{code_context}"
     );