refactor(monitoring): simplify notification system and remove auto-cleanup

- Replace state-based notifications with direct alert functions
- Remove auto-cleanup functionality from disk monitoring and configuration
- Simplify lock acquisition/release across all monitoring scripts
- Add execute_hana_sql helper functions for consistent SQL execution
- Remove state file tracking in favor of direct file operations
- Standardize error handling with exit codes on critical failures
- Clean up hana.conf by removing unused auto-delete directory settings

hana.conf

@@ -28,29 +28,6 @@ DIRECTORIES_TO_MONITOR=(
     "/usr/sap"
 )
 
-# --- Directories for Auto-Delete ---
-# These directories will be automatically cleaned when disk space is low
-# Format: "mount_point:directory_path"
-# The script will check if a monitored directory is on the same mount point
-# as an auto-delete directory and can clean it to free up space
-# NOTE: Do NOT include HANA system logs like /hana/log - only include
-# directories with safe-to-delete files like backup logs, temp files, etc.
-DIRS_FOR_AUTODELETE=(
-    "/hana/shared:/hana/shared/backup/schema/DB_NDB"
-    "/hana/shared:/hana/shared/backup/schema/SYSTEMDB"
-    "/hana/data:/hana/data/temp"
-    "/usr/sap:/usr/sap/trans/log"
-    "/usr/sap:/usr/sap/hostctrl/work/log"
-)
-
-# --- Disk Auto-Delete Configuration ---
-# Minimum free space percentage to maintain after cleanup
-MIN_FREE_SPACE_AFTER_CLEANUP=5
-# Maximum age of files to delete (in days)
-MAX_FILE_AGE_DAYS=7
-# Enable automatic cleanup when disk usage exceeds threshold
-AUTO_CLEANUP_ENABLED=true
-
 # --- Thresholds ---
 DISK_USAGE_THRESHOLD=85
 TRUNCATED_PERCENTAGE_THRESHOLD=50