CRITICAL FIXES: Security vulnerabilities in reference-db.sh and common-functions.sh

SECURITY FIXES:
1. SQL Injection (reference-db.sh:183)
   - Escape database names with backticks in WHERE clause
   - Changed: WHERE table_schema='' → WHERE table_schema=``
   - Prevents malicious database names from breaking SQL queries

2. Password Exposure (reference-db.sh:166)
   - Stop passing password on command line (visible in ps aux)
   - Changed: mysql -uadmin -p${plesk_mysql_pass} → MYSQL_PWD env var
   - Passwords no longer exposed in process listings
   - Added unset MYSQL_PWD at end of function for cleanup

3. Race Condition in Temp Files (common-functions.sh:173)
   - Replace mkdir -p with mktemp -d for secure temp directory creation
   - Changed: mkdir -p "$TEMP_SESSION_DIR" → mktemp -d -t server-toolkit.XXXXXX
   - Prevents race condition attacks on predictable paths

Testing: All changes validated for syntax and behavior

.sysref.beta.timestamp

@@ -0,0 +1 @@
+1773966543