feat: add Transmission monitoring to dashboard

- Add backend API for Transmission RPC integration
- Create frontend page with torrent and tracker status
- Add health monitoring script
- Display daemon status, speeds, and tracker errors
- Support reannounce, start/stop actions

scripts/check-transmission-health.sh

@@ -0,0 +1,52 @@
+#!/bin/bash
+# Transmission Health Check Script
+# Monitors Transmission daemon and tracker connectivity
+
+TELEGRAM_BOT_TOKEN="${TELEGRAM_BOT_TOKEN}"
+TELEGRAM_CHAT_ID="${TELEGRAM_CHAT_ID}"
+
+send_alert() {
+    local message="$1"
+    if [ -n "$TELEGRAM_BOT_TOKEN" ] && [ -n "$TELEGRAM_CHAT_ID" ]; then
+        curl -s -X POST "https://api.telegram.org/bot${TELEGRAM_BOT_TOKEN}/sendMessage" \
+            -d "chat_id=${TELEGRAM_CHAT_ID}" \
+            -d "text=🚨 Transmission Alert: ${message}" \
+            -d "parse_mode=HTML" > /dev/null
+    fi
+}
+
+# Check if Transmission daemon is running
+if ! ps aux | grep transmission-daemon | grep sc-transmission | grep -v grep > /dev/null; then
+    send_alert "Transmission daemon is not running!"
+    echo "ERROR: Transmission daemon is not running"
+    exit 1
+fi
+
+# Check recent logs for tracker errors
+LOG_FILE="/volume1/@appdata/transmission/transmission.log"
+if [ -f "$LOG_FILE" ]; then
+    # Count recent tracker errors (last 100 lines)
+    ERROR_COUNT=$(tail -100 "$LOG_FILE" | grep -c "Announce error: Could not connect to tracker")
+
+    if [ "$ERROR_COUNT" -gt 50 ]; then
+        send_alert "High number of tracker errors detected: ${ERROR_COUNT} in recent logs"
+        echo "WARNING: ${ERROR_COUNT} tracker errors found"
+    fi
+
+    # Check if log is stale (no updates in last hour)
+    LOG_AGE=$(find "$LOG_FILE" -mmin +60 2>/dev/null)
+    if [ -n "$LOG_AGE" ]; then
+        send_alert "Transmission log hasn't been updated in over an hour - daemon may be stuck"
+        echo "WARNING: Log file is stale"
+    fi
+fi
+
+# Check if RPC port is listening
+if ! netstat -tln 2>/dev/null | grep -q ":9091 " && ! ss -tln 2>/dev/null | grep -q ":9091 "; then
+    send_alert "Transmission RPC port 9091 is not listening"
+    echo "ERROR: RPC port not listening"
+    exit 1
+fi
+
+echo "OK: Transmission health check passed"
+exit 0