Refactor redeploy script and improve documentation

- Updated `redeploy-ubuntu.sh` to enhance error handling and user feedback during the redeployment process.
- Revised `REDEPLOY_GUIDE.md` for clarity and added troubleshooting tips based on user feedback.
- Improved structure and navigation of deployment documentation for better accessibility.
- Minor adjustments to `redeploy-hint.md` to reflect recent changes in automation examples.

check-service-status.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+
+echo "=========================================="
+echo "AI Review Service - Status Check"
+echo "=========================================="
+echo ""
+
+echo "1. Service Status:"
+systemctl status ai-review.service --no-pager
+echo ""
+
+echo "=========================================="
+echo "2. Last 100 lines of logs:"
+echo "=========================================="
+journalctl -u ai-review.service -n 100 --no-pager
+echo ""
+
+echo "=========================================="
+echo "3. Checking files:"
+echo "=========================================="
+echo "Backend exists: $([ -d /home/user/code-review-agent/backend ] && echo 'YES' || echo 'NO')"
+echo "Frontend exists: $([ -d /home/user/code-review-agent/frontend ] && echo 'YES' || echo 'NO')"
+echo "Public dir exists: $([ -d /home/user/code-review-agent/backend/public ] && echo 'YES' || echo 'NO')"
+echo "venv exists: $([ -d /home/user/code-review-agent/backend/venv ] && echo 'YES' || echo 'NO')"
+echo ".env exists: $([ -f /home/user/code-review-agent/backend/.env ] && echo 'YES' || echo 'NO')"
+echo "DB exists: $([ -f /home/user/code-review-agent/backend/review.db ] && echo 'YES' || echo 'NO')"
+echo ""
+
+echo "=========================================="
+echo "4. Manual start test:"
+echo "=========================================="
+echo "Run this command to see actual error:"
+echo "cd /home/user/code-review-agent/backend && source venv/bin/activate && python -m uvicorn app.main:app --host 0.0.0.0 --port 8000"
+