fix: Resolve temp directory permission issues for policy creation

- Changed default temp directory to local backend/temp instead of system temp
- Added write permission test during temp directory initialization
- Implemented fallback to OS temp directory if local temp fails
- Added unique random suffix to policy filenames to avoid conflicts
- Set proper file permissions (0o644) when writing policy files
- Improved error handling for temp directory creation failures
- Fixed fs.constants reference for file access checks

This resolves the EACCES permission denied error when creating policies
in Docker/production environments.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.claude-flow/metrics/performance.json

@@ -0,0 +1,9 @@
+{
+  "startTime": 1755632885258,
+  "totalTasks": 1,
+  "successfulTasks": 1,
+  "failedTasks": 0,
+  "totalAgents": 0,
+  "activeAgents": 0,
+  "neuralEvents": 0
+}