security: redact secrets from auxiliary and vision LLM responses

LLM responses from browser snapshot extraction and vision analysis
could echo back secrets that appeared on screen or in page content.
Input redaction alone is insufficient — the LLM may reproduce secrets
it read from screenshots (which cannot be text-redacted).

Now redact outputs from:
- _extract_relevant_content (auxiliary LLM response)
- browser_vision (vision LLM response)
- camofox_vision (vision LLM response)

tools/browser_tool.py

@@ -1048,7 +1048,9 @@ def _extract_relevant_content(
         if model:
             call_kwargs["model"] = model
         response = call_llm(**call_kwargs)
-        return (response.choices[0].message.content or "").strip() or _truncate_snapshot(snapshot_text)
+        extracted = (response.choices[0].message.content or "").strip() or _truncate_snapshot(snapshot_text)
+        # Redact any secrets the auxiliary LLM may have echoed back.
+        return redact_sensitive_text(extracted)
     except Exception:
         return _truncate_snapshot(snapshot_text)
 
@@ -1740,6 +1742,9 @@ def browser_vision(question: str, annotate: bool = False, task_id: Optional[str]
         response = call_llm(**call_kwargs)
         
         analysis = (response.choices[0].message.content or "").strip()
+        # Redact secrets the vision LLM may have read from the screenshot.
+        from agent.redact import redact_sensitive_text
+        analysis = redact_sensitive_text(analysis)
         response_data = {
             "success": True,
             "analysis": analysis or "Vision analysis returned no content.",